Dr. Michael F. Holick, Ph.D., M.D.
Dr. Michael F. Holick

Welcome to VitaminDHealth.org

Posted by mfholick on November 26, 2008 under Vitamin D | 95 Comments to Read

 Michael F. Holick, PhD, MD
 Professor of Medicine, Physiology and Biophysics
 Director of the General Clinical Research Center
 Director of the Vitamin D, Skin and Bone Research Laboratory
 Director, Biologic Effects of Light Research Center
 Boston University Medical Center
 

               Help spread the word about Vitamin D deficiency in 2013:

Dr. Holick’s new book The Vitamin D Solution is now available! Click on the book cover for more information on how to order.

Vitamin D is not a vitamin but a hormone. It is unique in that it is made in the skin as a result of exposure to sunlight. Photosynthesis of vitamin D has been occurring on earth for more than 750 million years. Some of the earliest life forms that were exposed to sunlight for their energy requirement were also photosynthesizing vitamin D. Both children and adults have in the past depended on adequate sun exposure to satisfy their vitamin D requirement. It is well documented that at the turn of the last century upwards of 80% of children in the industrialized, polluted cities of northern Europe and northeastern United States suffered from the devastating consequences of vitamin D deficiency rickets. The skin has a large capacity to make vitamin D. Exposure of a person in a bathing suit to a minimal erythemal dose of sunlight, which is typically no more than 15-20 minutes on Cape Cod in June or July at noon time, is the equivalent to taking 20,000 IU of vitamin D orally. It is now well documented that in the absence of any sun exposure 1,000 IU of vitamin D3 a day is necessary to maintain healthy levels of 25-hydroxyvitamin D in the circulation. An analysis of the NHANES III data has demonstrated that neither children nor adults are receiving an adequate amount of vitamin D from their diet or from supplements.

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Figure 1: The causes and consequeces of vitamin D deficiency (click the image for a larger version)

Is there any advantage to being exposed to sunlight to produce vitamin D rather than taking a pill that contains an adequate amount, i.e., 1,000 IU of vitamin D3 It is known that when exposed to sunlight the vitamin D that’s made in the skin enters the dermal capillary bed, and essentially 100% is bound to the vitamin D binding protein. When vitamin D is ingested, it is incorporated into the chylomicrons and is transported through the lymphatic system, which in turn, is deposited into the venous system where it eventually is metabolized in the liver to 25-hydroxyvitamin D. As a result, no more than 60% of the vitamin D that is ingested is bound to the vitamin D binding protein, whereas the other 40% is mostly bound to lipoproteins. Thus, the vitamin D that is made in the skin has a longer half-life in the circulation than it does when ingested from the diet or from a supplement. Furthermore, the vitamin D produced in the skin from sun exposure is free, unlike a vitamin D supplement. You can never become vitamin D intoxicated from sun exposure, but you can if you take too many vitamin D pills.

90-95% of most people’s vitamin D requirement comes from casual exposure to sunlight. Why is there such a controversy about sensible sun exposure as a recommendation to satisfy our vitamin D requirement? The sun has been demonized, and as a result, most of the world’s population has been brain washed into thinking that any exposure to sunlight is bad medicine. This is unfortunate since there is essentially no substantiated scientific evidence to suggest that moderate sun exposure either significantly increase risks of squamous and basal cell carcinomas, and more importantly, the most deadly form of skin cancer melanoma. There is no question that excessive exposure to sunlight and sun burning experiences significantly increase risk of both basal and squamous cell carcinoma. However, these cancers are often easily detected, and if detected early, are easily treated and often cured. Melanoma on the other hand, is a very aggressive and deadly form of skin cancer. However, most melanomas occur on the least sun exposed areas, and a recent meta-analysis of 35 studies suggests that occupational exposure to sunlight decreases risk of developing melanoma.

Why not take advantage of sensible sun exposure? Not only do people feel better but they also will obtain their vitamin D requirement during the spring, summer and fall. It is possible to maintain adequate vitamin D stores by taking an adequate amount of vitamin D from a supplement. It is extremely unlikely that a person can get an adequate amount of vitamin D from their diet, however. The major issue of obtaining vitamin D from a pill is that the person has to remember to take the pill, and they have to be able to find a pill that contains the needed amount of vitamin D, i.e., 1,000 IU of vitamin D3.

There needs to be a reevaluation of the important role that sensible sun exposure has in providing vitamin D for the world’s population. Indeed, in Australia and New Zealand where the incidence of skin cancer are the highest in the world, the New Zealand Bone and Mineral Society in collaboration with the Australian College of Dermatologists and Cancer Council of Australia have recommended that a balance is required between avoiding an increased risk of skin cancer and achieving enough UV radiation to maintain adequate vitamin D levels. I believe Charles Shultz said it the best in his Peanuts comic strip where Linus is sitting in the school yard, opens his lunch to find a note from his mother encouraging him to “make good friends, get good grades”, and she notes, “I hope that you are sitting in the sun, for a little sun is good as long as we don’t over do it. Perhaps 10 minutes a day this time of the year is about right.” He was right on target. Hopefully this message will be heard, and this recommendation will be adopted world-wide.

References:

Holick, M.F. Vitamin D: Importance in the prevention of cancers, type 1 diabetes, heart disease. and osteoporosis. Am J Clin Nutr 2004; 79:362-371.

Holick, M.F. Resurrection of vitamin D deficiency and rickets. J Clin Invest 2006, 116(8):2062-2072.

Holick, MF. Vitamin D Deficiency. N Engl J Med 2007;357:266-281.

  • Judy Converse MPH, RD, LD said,

    I provide nutrition assessment, care, and monitoring for children with developmental and learning disabilities – a population usually overlooked for nutrition concerns. Between their poorer food intakes, intestinal infections, and frequent malabsorption issues, they must surely have poor D status – I’d wager, worse than the already questionable D status of typical peers. Nutrition deficits in autism have emerged in the literature already for other nutrients like calcium, zinc, or iron. Fascinating topic, and the 3 hour lecture I attended by Dr Holick never once became dull.

  • Karen Neil said,

    The lecture on Vitamin D was very interesting. Why is it that doctors do not evaluate for proper levels in patients? It seems to me that they could diagnose many of the problems that patients complain of, by this blood test. How come the doctors aren’t doing this?

  • Evelyne Tourigny said,

    I think the major issue of obtaining vitamin D from a pill such as 1,000 IU of vitamin D3 is that a person can elevate his D125.
    Dr Holick do you think that too much D3 can be dangerouse? Why The FDA only allows D2 for treatment???

  • Carolyn Hudson, RD, LD said,

    Any chance we can get the Dec 10/2008 Webinar put back on this site? I continually have people ask me about it and would like to direct them to it again.
    Thank you so much!
    Carolyn Hudson, RD, LD
    Midwest Dariy Association
    2015 Rice Street
    St. Paul, MN 55113
    1-800-406-MILK (6455)

  • GEORGE MANDLER said,

    Dear Dr Holick,
    At the Integrative Healthcare symposium in NYC you spoke that breast milk is deficient in vitamin D and giving vitamin D to the mother does not help the baby.
    Can you please point me to your research showing the if a mom is replete in Vitamin D then her breast milk is still deficient.

    There are several published studies from Hollis and Wagner from U of SC that show breast milk 25(OH)D levels correlate well with plasma 25(OH)D levels. Here is one:
    Am J Clin Nutr. 2004 Dec ;80 (6 Suppl):1752S-8S Pub Med ID: 15585800

    thank you
    George Mandler

  • mary mcdarby said,

    my blood tests showed my vitamin D to be well over the established limits.(I think about a 40); But I did have elevated para-thyroid hormone. The 24 hour urine test proved to be normal. However, I was advised to take more vitamin d. I now take a 1000mg daily supplement in addition to the additive in my calcium supplement (2/day) and the vitamin d in my multiple vitamin. In addition, although I live in the Northeast, I am outside whenever I can be (daily from April to October about 5 hours). Can you overdose on Vitamin D?

  • Kali said,

    A doctor recently told me that us people in the Pacific Northwest (in Washington state) should take total 1,000-2,000iu of vitamin D. My multivitamin has 800iu and I just got a vitamin D supplement of 400iu. Do you think that’s ok? I also take total 950iu of Calcium, because to prevent Osteoporis, (recommended by another dr. of mine)like my mom has. (I’m 39)

  • Anna said,

    Mary,

    At 40 ng/mL you are not “well over” the established limits at all, though the majority of doctors will think your level is fine (my very conventional endocrinologist thought the 40s was fine for me, but my more creative and thoughtful primary doc thought I should get it higher.

    Your level is just barely inside the bottom of the reference range, which is 30 ng/ml by most labs. At least over 50ng/ml is generally considered a more optimal level by those who keep up with Vitamin D research.

    Living in the Northeast, you are lucky to even have a D level that high (all but one of my upstate NY family members were extremely deficient when they tested this winter, even the teenage girls, due to overcast climate, little or no D3 supplementation other than skimmed milk, and liberal high SPF sunscreen use).

    Taking 1000iu daily you won’t have to worry about toxicity at all. You can take several times that amount without worry. Our family tries to keep our 25(OH)D level between 70-80 ng/ml, and we need to take 1000iu per EACH 25 pounds of body weight to achieve that in the coastal San Diego region. That’s 3000iu for our 10 yo son during the school year when he’s indoor more, 5000iu daily for me (age 47), and 8000iu for my husband (age 54). Even in SD, CA, I could only get my level to 44 taking 2000iu daily. I tried getting more (prudent) sun instead of supplements last spring and summer (including a 2 wk vacation in Italy) and my level dropped to 40 ng/mL in late August, when I would have the highest levels of the year. Purdent sun exposure wasn’t enough. 5000iu D3 daily brought it up to a nice 76 ng/ml this winter and I feel much better than I’ve felt in years – more stamina & energy, more resistance to colds, better winter mood.

    Good luck to you.

  • Hend said,

    Dr. Holick-I am a Muslim woman who covers. I am studying dietetics and one of my concerns is that many Muslim women are not getting enough Vitamin D–either from the sun or from food or supplements. I am trying to get some help to conduct a study or some sort of education for Muslim women. Could you give me any advice…point me to some tools?

  • Debra said,

    I have been diagnosed with RA and also Vitmin D level is deficient at 17.I was put on a Rx of Vitamin D for 8 weeks then told by my rheumatologist to take caltrate with D.I just started having the same muscle pain and fatigue that made me seek attention in the first place. My liver enzymes are also slightly elevated and I take 5mg of Folic acid per day for this.
    My question is should I try to get more sun exposure, or wait until my doctor gets the level results back to see if I am still deficient? I believe in my own opinion it has deceased and since I know I have a issue already it is worrisome.

  • Anna said,

    Is there any danger in a very high 1,25 level??? Mid May, my 1,25 level was 130 (normal is 6-62) and yet my OH was only 46.2. I had been tanning (NYC murky sunlight, some tanning booths and supplementing with around 800 iu of vitamin d3 per day.) I subsequently have upped my supplementation to 2,400 IU per day plus outdoor sunshine. I’ve been feeling inexplicity exhausted and often nauseaus? Can I have gone toxic??? I weigh 105 pounds, am 46 year old female. My diet is near paleo style: NO dairy — just organic meats, fish, organic veggies, nuts and fruits. I drink all manner of teas and some coffee. I eat sardines & salmon with bones and also chew on chicken bones and eat the marrow. No calcium supplements. I take hypothyroid meds (armour plus cytomel). Anyone have any lay persons non-medical advice thoughts on what could be causing the fatigue, weakness and intermittent nausea???

  • Lamya said,

    Dr. Holic,
    My vitamin D level was found to be 17nmol/l, i started taking vitamin D3 but it made me very photo sensitive even very strong sunsblocks are not effective with me. only 15 min indirect sun exposure would make my face as if just came out of an oven so i stopped taking vitamin D and the sun is more tolerable for me now but my levels are still low!!
    do you have any suggestions?

  • D.L. Smith said,

    Are you aware of any studies that have looked at whether or not there is a difference in the “biological potency” of supplement-induced vitamin D vs UVR-induced vitamin D?

  • Kurt Butler said,

    Shame on Dr. Holick for appearing on Coast-to-Coast-AM right after yet another of the program’s many hysterical anti-vaccination propaganda sessions and not taking George to task for it and registering a strong dissent. These nuts are killing people. Responsible physicians should boycott the show until it gives equal time to vaccination rationalists. Otherwise you lend credibility to the garbage. Also, an award from the Linus Pauling foundation (or whatever it’s called) is nothing to be proud of. Pauling and his followers
    promote(d) lots of pseudoscientific clap-trap. After decades of promoting the miracles of massive (and dangerous) doses of vitamin C for everything under the sun there is still no evidence for their claims, yet they persist. However, I applaud your excellent work on vitamin D.

  • joe said,

    Are there vitamin D benefits associated with the light produced by tanning beds?

  • Ann said,

    I was feeling very tired and sluggish, went to my doctor who ran full battery of tests. My vitamin D level was only 10. Severely deficient. I was put on 50000 iu three times a week and immediately felt better. Took this dosgae for 3 months. Then my doctor took me off saying I was “full” and should be fine. About 8 weeks after I stopped taking the D I began to feel sluggish and tired. Went back to the doctor told him my D was low again- he said it couldn’t be, he had filled my store house with D. I asked for another D test anyway, and sure enough I was very low again. So, I am on 50000 iu, once a week – feel better again. Had not realized just how much we need out D.

  • Johanna Sayre said,

    A wonderful website, but it would be good–if possible–to have responses to some of the issues raised.
    So far missing in my perusal of the website, are age references, and ultra-violet, and infra-red lamp exposure, esp. in the winter.
    Age: I am 81, have serious health issues from osteoporosis, to RA factor, Hep. C, and very ‘weak’ input from the primary doctor and specialists as to how/where these aspects intersect and how e.g. Vit D fits into the picture.
    I have a long background of sun exposure information. From being toddlers we were put into the sun, for carefully monitored time, from 10′ building up to 20′ or 25′ then back down, then back up again, over weeks of this in the summer. My mother put rendered pig’s fat on us (unsalted), and a little white hat. In the winter ultra-violet lamp exposure was part of the routine. It started with 3′ going up to 8′ to 10′; then down etc. Distance from the lamp was as important as duration.
    I remember that being on water, and in snow was a consideration in the type of sun exposure, and protective care, esp. eyes. Sun baths in winter were of course plus clothes, but the idea of being on a deck chair in blankets, in the sun, has been with me from early childhood.
    All this, I would say was quite common knowledge.
    Later, things were more irregular and out of control because of the war. But still later, one summer, I went to a ladies’ sunbath regularly. For about two years hence it was a time of being and feeling well.
    This summer I started–somewhat late, alas–with sun baths, at a time when I am beset by health problems. The sunbaths are just wonderful, and I long for sunny days.

  • Mel said,

    I had severe fatigue ,nervous issues and alot more symptoms start about a yr ago and several specailists and tests later my vit D was low (D2 was 4 ,D3 was 17) total D was 21……..also my bun alt als levels were the “low” normal….was weird with all my symptoms and no findings at first , i was labeled anxious,depressed and basically hypochondriac! i was humiliated…most doctors dont agree that vit D def can have a huge affect on ones health…should more doctors be educated on this world wide issue?

    MY issue is i dont seem to tolerate taking D3 my body gets lethargic after taking it and i even pass out…this is with any amount. of course this made me look even more insane …but ive come to find out im not the only one like this.

    i handle sun well but dont think im getting enough….im in NC and soon will be moving to NY even worse for sunshine…
    my body /muscles are losing weight , i have pains in legs and all over… blood press goes up and down….
    this vit D seems to effect the whole body systems….

    my whole body seems to be off…..i read about a sun lamp on sperti i think its called…….will this lamp really work for 300 dollars?
    or is the FL sun best and worth the move there?

    i only take 600iu of plain D from right aid its ergocalciferol not D3 which i cant seem to tolerate…its a hard chalky pill…..and i seem ok with it somedays…..i try to drink almond milk with D2 and eat eggs alot….for D3 but i know this isnt sufficient.
    its a catch 22 here most high cholesterol foods have D3 but you need D3 to regulate it….!so if your deficient your cholesterol will be high!

    I looked into D3 and its source and most are made from lanolin or sheeps wool……..im highly allergic to wool in general could this be why i cannot even take a supplement that was processed from it????

    i noticed too that i dont seem to process fats the same as i use to , cant tolerate fish oil or certain fats…my stool floats……..never had this before.

    i was told to take D2 50,000 iu week but refused only because if my body cant tolerate a sm amt at this point what would happen with such a high dosage…i think sm amt over long periods is best in my case.

    for now i try to get sunlight on the porch but would like to know what hrs here in NC are best for the rays i need.? and what about NY?

    this is very scarey going through this D deficiency and i wonder if its not the cause of most diseases in this world….ive never felt worse ! and hope someone comes up with some alternative way to get D for pple who cant tolerate it or for pple i know who just dont absorb it…..

    Is there hope for us doctor ????

  • Saida Abdul-Aziz, RN said,

    You have inspired me to change my approach to community health. I also changed my Masters project to discss the cult\ural implications of Vitamin D Deficiency in African American Veiled Muslim women and have started to look at the possibility of completing research on this phenomena at the Doctoral level. I am wondering if I have sited you extensively and wanted to have permission to use your quiz aws an assessment tool to have school nurses assess their knowledge and seek more. I have cited your work so that it may be located easily. May I have permission or is ther a charge. I do not intend to sell or distribute your work without crediting. Would appreciate a response and discussion when I complete my MSN/MBA-HCM about taking your work to nurses Internationally.

  • Evelyn said,

    I was taking 1000 IU of a liquid Vitamin D3…[one used by researcher here in Canada] for about 4 years. My 25[OH]D level was 94nmol/L.
    In Jan.2009 I upped my Vitamin D to 3000 IU. At the end of the summer I had a cataract removed and the eye doctor insisted that I use Maxitrol[antibiotic& steroid] eyedrops in my eye after surgery to prevent infection. even though I’m allergic to steroids. After a few days on the eyedrops I had severe muscle,bone,joint and ligament pain.I also have RA which up to this point I felt was benefiting from Vitamin D.I went for a Vitamin D blood test and my blood level dropped from 94 while on 1000 IU vitamin D down to 81 while taking 3000 IU. I had upped Vit D to 5000 IU just before the surgery.
    What caused my Vitamin D level to drop and for me to have such pain?Could it have been the steroid eyedrops depleting the Vitamin D?
    I would appreciate a reply through my email from Dr,Hollick if possible.

  • Jeannie said,

    Dear Dr. Holick:
    After listening to your interview with Alan Chartock of WAMC, I asked my PCP for a 25-hydroxyvitamin D test. My level is 17.5. I live in the northeast and am only outside while commuting. Can I bring level up to acceptable levels by over-the-counter supplementing? And if so, how much would I take?

  • V.P.Veluswamy MD said,

    Dr Holick, I am a retired Physician. I attended the SMA conference in Dalla TX in Dec 09. Your talk on Vitamin D was both enj0yable and instructional. I teach preventive cardiology. I have to look at osteoporosis as a preventable disease and inform the public. Is your lecture on Vitamin D, available as a DVD?? If so I would like to get one. If not I recommend that you produce one for Physicians and I will buy a few to give it to my physician friends in USA and abroad. V.P.Veluswamy MD 941-3834249.

  • Alex said,

    DR.Holick
    I have had lots of problems going on with me and nothing Dr.s can’t find nothing wrong with me!I lost 27 lbs in 2 months and my DR. says it’s Fibromalgia and IBS!! My Vitamin D level is 19 and i have been diagonse with Hypocalcema before in the past while i was in hospital for stomach pains my Sed rate is @ 39 and some protein in urine.Dr checked calcium and their normal. Does Perdisone affect lab results? And what Dr. Should i get refered to? or should i go with anti-deprsents and treat (fibro) and (IBS)….

  • Janet Beale said,

    What is upper limit of Vitamin D supplementation? I have been on 50,000 units twice a week for six months without testing and I am concerned I am getting too much.

  • Gabriela said,

    I’m 38 and my doctor said that my level of vit. D is like a woman in hers 70′s. I’m really scared. I’m from North Brazil and I was constantly exposed to the sunlight and since I came to America I stopped this exposure. Do you think that this is the reason that I have this low level of vit. D? I also got obese; I’m 40 pounds over my normal weight. I would like to increase the level of vit D in my body as soon as possible. The days here where I live are always cloudy; we are still in winter time. What do I do?

  • clay berger said,

    Bravo, the sun is no longer a villain! I practice the George Hamilton Plan. He is known for his fabulous tan and so-so acting. In an interview in a men’s magazine, he was asked what sun block he used. He replied he never used any. He stated that he never stayed out in the sun long enough to burn. I adopted that program and get 15 minutes on the front and 15 on the backside and call it a day, all year round. It works great even in the winter.

  • Savage said,

    Hi,
    I recently met Dr. Holick at the Mushroom Festival in Kennett Sq. PA. Unfortunately I didn’t have the opportunity to ask if he has had any experience with applying vitamin D directly to actinic keratosis on the skin. I have had several actinic keratosis fade dramatically in just a couple of days! Is this uncommon? should I stop this self treatment?

  • Rune said,

    In the forum of clusterheadaches.com, numerous sufferers of Cluster Headache reports impressing results shortly after starting taking 10.000 IU daily (and Calcium, Magnesium and Fish oil).

    Cluster headache is an extremely painful condition and no very good preventive exists. But people who have been chronics for years have very promising reports: Like being completely pain free for months!

  • Jan Dahlin Geiger said,

    Dr. Holick, so loved your book, thank you for being such a strong pioneer. I am looking for the D Sun Solution sunscreen you mentioned at the end of your book, but cannot find their website nor any place that sells it. Do you have an updated website for them or do you know if they went out of business?

  • Lance Strish said,

    It looks like DrGreger changed his VitD recommendation from 4000IU/day to 2000IU/day (or 15-30min sun) last month:
    http://www.facebook.com/NutritionFacts.org/posts/193068787424836

    I think these are his studies changing his decision for 20-30ng/ML is safest and not 50-70 for Vitamin D:
    “Vitamin D deficiency is common in healthy adults
    and children as well as in the chronic kidney disease (CKD)
    population. What was once a disease of malnourished children
    in the developing world has re-emerged and reached
    pandemic proportions. In parallel with this development,
    there is a growing awareness that vitamin D is not simply a
    ‘calcaemic hormone’ but plays an important role in the
    prevention of cardiovascular disease, infectious and autoimmune
    conditions, renoprotection, glycaemic control and
    prevention of some common cancers.

    Although numerous studies have not
    observed any adverse effects of higher
    vitamin D status, a few have. Historically,
    the main health risks associated with
    excessive vitamin D are linked with
    abnormal plasma calcium concentrations.
    Excessive vitamin D is recognized to
    cause hypercalcemia by increasing intestinal
    calcium absorption or by increasing
    mobilization of bone calcium. Although
    hypercalcemia is uncommon with intakes
    less than 10 000 IU/d,3 knowledge of
    non-calcium-related adverse events is
    limited. At least some evidence suggests
    that high vitamin D status may be associated
    with increased risk of some cancers.
    In a large case control study of prostate
    cancer in Finland and Norway, both
    low (32 ng/mL)
    25(OH)D concentrations were reported
    to be associated with an increased incidence
    of prostate cancer (50% and 70%,
    respectively) compared with individuals
    with serum 25(OH)D concentrations
    between 16 and 24 ng/mL.4 A direct relationship
    between higher vitamin D status
    and the development of esophageal
    carcinoma also has been observed in
    Chinese men.5 Interestingly, all the participants,
    including those in the highest
    quintile, were vitamin D deficient (26.2
    ng/mL) with a 3-fold increased risk of
    pancreatic cancer compared to individuals
    with the lowest baseline status (<12.8
    ng/mL). Overall, these studies suggest
    there may be an optimum status and that
    values below or above may increase risk
    of certain types of cancer.
    Adverse events associated with high vitamin
    D status other than cancer also have
    been observed. Recent data from large
    epidemiologic studies, including the Third
    National Health and Nutrition Examination
    Survey (NHANES III) and the Framingham
    Heart Study, suggest that a “U-shaped
    curve” relationship exists with all-cause
    mortality and the incidence of cardiovascular
    disease because both low and high
    25(OH)D concentrations elevated risk.7,8
    In the NHANES III study, higher mortality
    risk was observed in participants
    with 25(OH)D above 49 ng/mL. In the
    Framingham study, the lowest cardiovascular
    disease risks were found in
    participants with baseline 25(OH)D levels
    of 20 to 25 ng/mL but increased with both
    lower and higher values,8 thus suggesting
    that increased cardiovascular risk occurred
    at levels below 30 ng/mL. Furthermore,
    the optimal 25(OH)D levels for protection
    against cardiovascular disease and certain
    types of cancer may differ from those
    for bone metabolism or normal parathyroid
    hormone physiology. It should also
    be emphasized again that although few studies
    have shown adverse effects of
    higher vitamin D status, many do not.
    Regardless, it remains prudent to be cautious
    in case there are circumstances
    where ill consequences will surface."
    - from 'too much.pdf' http://is.gd/vT4Ogh

    “A vitamin D intake
    of 400 IU/day will only cause a modest increase in 25(OH)
    D levels by 2.8–4.8 ng/ml. To raise 25(OH)D levels from
    20 to 32 ng/ml requires an additional intake of 1700 IU/day
    [56] … Vitamin D intoxication is observed when 25(OH)D
    serum levels are > 100 ng/ml [1]. This topic is discussed
    in detail in subsequent sections.” from ‘how much too much.pdf’ http://is.gd/vT4Ogh

    And he may have seen more in 2011 as these are the 2010 studies.

    “There are currently no guidelines for the treatment of
    vitamin D deficiency in healthy adults. A vitamin D intake
    of 400 IU/day will only cause a modest increase in 25(OH)
    D levels by 2.8–4.8 ng/ml. To raise 25(OH)D levels from
    20 to 32 ng/ml requires an additional intake of 1700 IU/day
    [56]. Treatment regimens vary widely, ranging from
    600,000 IU of D2 or D3 as a single dose every 3 months
    (Stoss regimen), 2,000–4,000 IU daily for 3–6 months or
    50,000 IU three times per week. All of these regimens have
    been shown to increase circulating 25(OH)D levels, but
    only the regimens using at least 600,000 IU ergocalciferol
    were able to achieve adequate 25(OH)D levels [82]. The
    total dose used and not the dosing frequency determined the
    25(OH)D level achieved [82]. Only one study has looked at
    long-term treatment with ergocalciferol, reporting that
    50,000 IU every other week (median study period 2 years) is safe and prevents recurrent vitamin D deficiency [83].” – ‘how much is too much.pdf’

    I remember hearing some ills of Vitamin D this study on calcium supplements (I remember this study 2yrs ago in older people): ‘What jumped out at us was that higher vitamin D intake had a statistically significant association with having a greater volume of brain lesions. But before you worry about taking “too much” vitamin D, taking ample amounts of the “sunshine-and-seafood” vitamin doesn’t appear to be the main cause of artery calcification, as the researchers noted. In fact, as Dr. Ames reported, prior studies show just the opposite: having higher vitamin D levels in your blood appears to reduce the risk of dementia (Przybelski RJ, Binkley NC 2007). What’s to blame for damage to brains? Vitamin D or excess calcium?It appears much more likely that the brain-damaged volunteers’ high calcium consumption was the problem, not their vitamin D intake, which was merely adequate.’ http://newsletter.vitalchoice.com/e_article001190954.cfm?x=b11,0,w
    and also ‘Cancer dud’ http://www.longecity.org/forum/topic/41913-high-vitamin-d-a-cancer-dud/

    But this is the .png always linked in paleo community that looks to reach 50-60ng/mL vitamin D: http://is.gd/34nbhx http://is.gd/gk4zF0 I have read anecdotally that people who are obese (in comments section http://www.trackyourplaque.com/blog/2011/08/you-could-take-vitamin-d-or.html) may have to take more VitD (but the variation from person to person on how much to take to get adequate blood levels is different regardless of size as mentioned in the comments by DrWilliamDavis). Comment by someone: “I just wanted to add my experience on Vit. D3 supplementation.

    Two years ago in July I started supplementing 5,000 i.u. Vit. D3 a day. My sister had been found low, I live relatively the same lifestyle, and thought, “what the heck, I’ll start and get my blood tested in late winter next year”.

    That next March I had a blood test and found my blood levels to be at a whopping 32 ng/ml. My doctor said “fine, you’re within range” and I thought, “no, that’s not fine” and started to take 15,000 i.u. a day. In March again this year I had a blood draw, and expected to see a very high ng/ml of Vit. D. My actual result? It had raised to 45 ng/ml. I was floored that with that amount, my levels had only raised such a small amount.

    I will add that I am obese. I just wanted to give you my experience with D3 supplementation in case it helps someone else. I have now upped my supplementation once more to 20,000 i.u. a day, and if my next blood test is appreciably better, will hold at that level or drop back some. I will add that I haven’t had many if any colds this past year, so even if I have not attained a more optimal level (perhaps I can’t due to obesity) it’s still doing me a lot of good.”

    I have also read anecdotally from DrWilliamsDavis in the comments that amounts needed to maintain levels decrease as blood levels reach desired levels and testing every 6months is recommended

    I have seen mice on high D, not sunlight (look at the mice picture):
    http://healthcorrelator.blogspot.com/2010/01/vitamin-d-deficiency-seasonal.html ‘The figure below (click on it to enlarge), from Tuohimaa et al. (2009), shows two mice. The one on the left has a genetic mutation that leads to high levels of vitamin D-derived hormones in the blood. Both mice have about the same age, 8 months, but the mutant mouse shows marked signs of premature aging.’

    So what do you make of it?

  • Vicki said,

    I want to purchase a copy of your book, so I can give it to a friend who has just been diagnosed with Lymphoma
    and will be undergoing Chemotherapy.. I realize that you did not address this type of cancer in your lectures but I suspect her Vd levels are low and could use supplementation
    if for no other reason than to help with the side effects of the poison she is about to have invade you body.
    Back to the book .. I was unable to order on your website there seems to be a problem with domain name. Can you direct me to a another source
    thank you

  • katie said,

    Hi dr Hollick,
    I’m in my 37th week of pregnancy and I was wondering, since it’s winter and there isn’t enough sunny days anymore, what can I do to ensure that my newborn baby gets sufficient amount of vitamin D during winter period?
    Thanks in advance,
    Katie

  • Tam said,

    Dr Holick (or anyone with the knowledge) ~

    I recently purchased your Vitamin D Solution hoping to find some answers but I did not.
    IN May 2011 I was diagnosed with a Vitamin D “insufficiency” as my Endocrinologist stated. I went in there with CHRONIC nausea (my biggest symptom) as well as fatigue, back and neck pain and not able to lose any weight.

    Anyway, my test came back at Level 24. So, right away I began to take 1000 IU a day. Within about 2 weeks time I began to get EXTREME heart palpitations, which by the way I have never experienced in my life. I hadn’t connected the two until I decided to go off of the D. In a about a another week or two after stopping the D supplementation, the palps were completely gone. I tested this theory 6 times over the next 6 months. I added Magnesium (as I read that D may cause a Mag def. – but your book says the two are NOT connected) and it subsided them , but not enough.

    Each time I quit the D pills, within a week or two the palps are gone, not a trace. So, then I tested it out with the sun 3 times (only sun therapy, no pills)…..same thing.
    I am now ONLY getting my D from the Sun. However, the sun also gives me the palps just as the supplements did. Currently, I am getting about 2-3 hours of sun a week total(no sunscreen). I am tempted to go off of it again to stop these palps, they get extremely bad and are constant.

    And an interesting note to all of this craziness is that each time I go off of the D (sunshine or pills) my nausea returns within a couple weeks, just as the palps disappear.

    Now, I am taking Calcium because I don’t eat dairy. I am taking 1000mg a day.

    Anyway, my disappointment in your book is that it mentions nothing of possible side effects of D(other than toxicity) or any strange things like I am having. Major heart palps, muscle twitches and dizziness or lightheadedness. The lightheadedness just started within the last couple of weeks,which is why I saw the doctor and had the ECG done last week.

    I plan to start a Multi Vitamin (Vitamin Code – Family) soon, but I was waiting for these palps to finally get under control. I was hoping the Mag and Calcium would do it. But, so far, it only subsides them a bit. I was afraid adding a multi might make these worse. I am very frustrated and was really hoping your book would be more informative with cases like this.

    By the way, my heart is healthy otherwise, however I just had an ECG done that is now showing these. The doctor called them Premature Ventricular Contractions. I just know it must be lack of Calcium or Magnesium causing this.Why can’t I find the balance?? Do I really need the multi??

    Also, I had my D level checked again in Sept. 2011 and it had dropped to 23. I want to stay on my sun regimen, but these palps are scary and life impeding….but so is the nausea that I get IF I don’t get D. What is going on??? Can anyone shed some light on this???

    Frustrated, but Optimistic. :O)

  • Tam said,

    Also, what do you think of the Vitamin Code Family by Garden of Life multi vitamin? It contains 1000IU of VD3. Would adding that as well as sun be beneficial?

  • admin said,

    I recommend that pregnant women take a vitamin D supplement that contains 2000 IU of vitamin D. This can be in addition to taking a prenatal vitamin that contains calcium and vitamin D.

  • admin said,

    Dear Tam,
    I have never observed any of my patients experiencing palpitations taking 1000 IU of vitamin D a day. Often I find that it is not the vitamin D but rather one of the other constituents in the vitamin D preparation that some patients are allergic to and have a variety of symptoms when they take vitamin D. However often when they switch to a different formulation they no longer experiences symptoms. I would be surprised if your symptoms recur when you are exposed to sunlight.

  • admin said,

    Dear Vicki,
    You can go to my website DrHolick.com for more information about where you can purchase the book. Alternatively you can go to Amazon.com.

  • admin said,

    Dear Lance,
    I have found that even my obese patients do well on 50,000 IU of vitamin D2 once a week which is equivalent to ingesting about 6000 IU of vitamin D a day. Some supplements are more bioavailable than others and this could be an explanation for why you need to take so much vitamin D. Also medications like prednisone and Dilantin increase the destruction of 25-hydroxyvitamin D requiring that these patients need more vitamin D to maintain their blood levels of 25-hydroxyvitamin D in the preferred range of 40-60 ng/ML.

  • admin said,

    Dear Tam,
    It is very reasonable to take 1000-2000 IU vitamin D supplement along with sensible sun exposure to guarantee vitamin D sufficiency.

  • Paula said,

    Dr Holick

    I have just received my second lab result showing my D level at 34 ng/ml. I did a test 3 months (October) ago it came back at 34.5 ng/ml. Prior to the test I had been supplementing with 5000 IU, and had been taking 2000 IU throughout the summer months. I suspect that I’m not absorbing my D supplements (oil based) and the weekly visit to the tanning salon isn’t helping. How does one deal with a malabsorption issue? Or, is the dosage I’m taking simply too low?

  • Jelle (mostlyraw.eu) said,

    I saw your presentation at http://youtu.be/Cq1t9WqOD-0 and wanted to thank you for it. I have been taking a tablet http://tinyurl.com/solgar-d3 weekly for the last year, but seeing your video, I want to increase this. Since this will become quite expensive to supplement the rest of your life. What Vitamin D (vegan) would you recommend and why? How can I separate the good from the bad? It may be helpful using http://www.iherb.com/Vitamin-D as supplier, but witch product. I would prefer to supplement weekly instead of daily, and how should one take the supplement, on an empty stomach or with fruits or vegetables or water?

  • Don said,

    Dr. Holick,
    A recent NYTimes article (January 12, 2012) reports on a Johns Hopkins study showing an inverse relationship between CRP and vitamin D for measured vitamin D levels from the low range on up. This is pretty surprising, and suggests that there could be a downside to vitamin D supplements. Have you had a chance to look into the details of this study?

  • Pamela Egan, NP-C, CDE, MN, ABAAHP said,

    The book sounds fascinating. I will most certainly be buying a copy, and if I find it worthy of my endorsement, will publish a review on my blog.

    I also have written extensively on the subject of vitamin D, and D3 in particular, and the majority of my readers visit my site to learn about the benefits of vitamin D3.

  • admin said,

    Dear Pamela,
    Thank you very much for your interest. Please let me know if I can be of any help.

  • admin said,

    Dear Don, I have read the publication. In my opinion there were several problems with the design of the study raising questions about the validity of the conclusions. Most intervention studies have shown that increasing vitamin D intake either decreases CRP or has no effect. From my personal experience with my patients I have not seen an increase in CRP when I raise their blood levels of 25-hydroxyvitamin D in the range of 40-60 ng/ml.

  • admin said,

    Dear Jelle, For vegans who do not want to take vitamin D3 because it is derived from lanolin from sheep’s wool, they can take vitamin D2 which is derived from yeast. A physician can prescribe 50,000 IU vitamin D2 once every 2 weeks which is what I do for my patients. You can take this on a full or empty stomach. Some patients have an allergy to the gelatin capsule so I advise them to cut the capsule in half and to place it in a little amount of milk, swirl it around and then drink it without the capsule. This also works for patients who have malabsorption syndromes.

  • admin said,

    Dear Paula, I have found that the patients who are obese need to take as much as 10,000 IU of vitamin D a day to satisfy their vitamin D requirement. The patients who do not raise their blood level of 25-hydroxyvitamin D after taking a relatively large vitamin D supplement as you have may be suffering from a malabsorption syndrome caused by celiac disease. Your doctor can test you for this. An alternative is to have your doctor write you a prescription for 50,000 IU of vitamin D and to take it twice a month. Most of my patients respond to this dose and maintain a blood level of 25-hydroxyvitamin D between 40-60 ng/ml.

  • admin said,

    Dear Jan, It is hoped that the sunscreen will come out this summer.

  • admin said,

    Dear Rune, I would be careful about taking 10,000 IU of vitamin D daily without having your blood level of 25-hydroxyvitamin D and calcium checked on a regular basis. You would like to maintain a blood level of 25-hydroxyvitamin D of 30-100 ng/ml (75-250 nmol/l).

  • Larry said,

    What about people living in Northern under/no exposure for months every year?

  • Treena Wynes said,

    There is still the common fundamental thinking that we must protect ourselves from the sun. I taught a public-speaking class for pharmacy students and a few did their power-point presentation on their last teaching session about the adverse effects of sunlight (with some medications). Basically sunscreen was highly encouraged as well as full body-coverage. They were also taught that 10 minutes of sunlight 3 times a day was sufficient amount of Vitamin D! I was shocked that this message is still being schooled. As a weight-loss counselor and an author I encourage sunlight and promote its benefits for mental health and stress management purposes.

  • Treena Wynes said,

    I must make a revision on my posting.

    They were taught that 10 minutes 3 times a WEEK was sufficient amount of Vitamin D, not a day. Therefore, 30 minutes of sunlight a week.

  • admin said,

    Dear Treena,
    The amount of sunlight required depends upon time of day, season of the year, degree of skin pigmentation and area exposed. From my experience a white person with skin type II who exposes their arms and legs to 10-15 minutes of sunlight between the hours of 10 AM and 3 PM in the middle of the summer at a latitude of 42° North, i.e. in Boston, 3 times a week would generate approximately 7000-10,000 IU of vitamin D. It is 3 times a week not 3 times a day. I always recommend some type of sun protection for the face and never get sun burned.

  • admin said,

    Dear Larry, I recommend that all adults take a 2000 IU vitamin D supplement every day throughout the year in addition to obtaining some vitamin D from sensible sun exposure in the spring summer and fall. That is what I do. As you realize you cannot make essentially any vitamin D in your skin between the months of November through February if you live at a latitude above Atlanta Georgia.

  • Donna Bicknese said,

    I am a general internist and have a 60 yr old female patient who is thin(BMI 21)who in Feb 2010 was placed on ergocalciferol 50000 IU weekly for vit D-25-OH of 34 ng/ml. By Feb, 2012 her her vit D-25-OH level increased to 75 ng/ml. This seems like a steeper increase than I see in most patients, but on the other hand, her BMI is 21. At a recent visit she revealed she drinks two quarts (half a gallon) of grapefruit juice a day. I’m wondering if there is a drug-drug interaction (so to speak) between ergocalciferol & grapefruit juice that would enhance the Vit D-25 levels in the blood? Thanks for any insights

  • admin said,

    Dear Donna,
    I am not aware of any interaction with grapefruit juice and vitamin D absorption. However I typically treat my patients with 50,000 IU of vitamin D once every 2 weeks. I believe she is taking too much vitamin D which is the explanation for the increase in her 25-hydroxyvitamin D.

  • Alexandria Cotie said,

    In your book, it states that Vitamin D will not be washed away if you shower after sun exposure. This morning (3/26/12) I read an article called “Little Sunshine Mistakes…Instead of Vitamin D” on Dr. Mercola’s website. It stated “vitamin D3 that is formed is on the surface of your skin does not immediately penetrate into your bloodstream. It actually needs to be absorbed from the surface of your skin into your bloodstream. The critical question then is: how long does it take the vitamin D3 to penetrate your skin and reach your bloodstream? If you’re thinking about an hour or two, like I did until recently, you’re wrong. Because new evidence shows it takes up to 48 hours before you absorb the majority of the vitamin D that was generated by exposing your skin to the sun! Therefore, if you shower with soap, you will simply wash away much of the vitamin D3 your skin generated, and decrease the benefits of your sun exposure.”

    What are your thoughts about this? Do you know what NEW evidence he is referring to?

    Thank you!

  • admin said,

    Dear Alexandria,
    Unfortunately Dr. Mercola is incorrect. He has never performed any studies to prove this. I have. When you are exposed to sunlight vitamin D is made in the living cells in your skin and therefore cannot be washed off.

  • Robert said,

    Dr. Holick,
    At the lattitude of Edmonton Alberta, 54 degrees north, approximately how many months of the year is it impossible to produce vitamin D naturally from the sun?
    Also, you say in your lecture that only 0.5% of the UVB actually makes it through the ozone to the surface of the earth. But you do not give the figure, except that it is small, of how much of the total radiant energy reaching the surface of the earth is UVB?

  • mike said,

    Dr. Holick,
    I have a vitamin D deficiency and can’t tolerate doses above 400 IU (rapid heartbeat, nausea, etc). So, I planned a trip to Fort Lauderdale Florida next week. However, I recently read conflicting information on whether you can get vitamin D from the sun at this time (January). My trip is too soon in time for me to get your book and I couldn’t find it at the bookstore so I don’t know if this is covered in your book. Any advice?

  • admin said,

    Dear Robert
    We did a study in Edmondton Canada and showed that essentially no vitamin D production occurs from mid-September until May. The total amount of irradiance from UVB is extremely small and I would estimate is less than 0.001%. Blood cholesterol levels are not related to vitamin D synthesis in the skin. Enhancing dermal capillary blood flow will not increase vitamin D synthesis but might enhance its transport into the bloodstream.

  • admin said,

    Dear Mike,
    You can make vitamin D in your skin throughout the year below a latitude of approximately 33°. You should be able to make vitamin D in your skin from 10 AM until about 3 PM in Fort Lauderdale even in January. This information is in my book that you can obtain from Amazon.com.

  • mike said,

    Dr. Holick,
    I read your great book and purchased the Sperti Lamp to address my vitamin D deficiency. I tried vitamin D supplements but anything above 500 IU from various brands or even food resulted in rapid heartbeat, insomnia, and trouble concentrating. Any research in this area? I believe I am skin type 3 but I burn using the lamp for 5 minutes. I use it every other day alternating between my back and chest. I will still get vitamin D if I use it for 4 minutes? Also, the manual says wait 24-48 hours until the burns go away. If I burn, I only need to avoid the burn area until it heals and can continue using it on other areas?

  • admin said,

    Dear Mike,
    Some people are more sensitive to ultraviolet radiation. You may very well be. You begin to make vitamin D in your skin as soon as you are exposed to ultraviolet radiation from the Sperti lamp. Therefore 4 minutes would be fine. You are correct you should not expose a burned area but an area that was not burned should be fine.

  • mike said,

    Dr. Holick,
    In the part of your book with the tables on months when you can have vitamin D production after vitamin D winter, does vitamin D production start at the beginning of the month after winter or later? For example, I read elsewhere that vitamin D winter in Pennsylvania doesn’t end until mid-March.

  • Joan Peterson said,

    Is the absorption of supplemental D3 better when provided in gel capsules rather than in pill form?

  • Daniel said,

    Dr. Hollick,

    have you ever come accross someone who isn’t capable of producing vitamin d after exposure to sunlight? Is that possible?

    My 25 OH levels fall causing rickets. I sunbathe a lot, but my levels wouldn’t rise, they remain at 6-7 ng/ml, so I always end up having to supplement. Is that normal? I got rickets at 26 years of age when my 25 oh levels fell to 5 ng/ml. Before that I’ve been healthy all my life and had never had any problem with vitamin D.

  • admin said,

    Dear Mike,
    Vitamin D production begins gradually and if you live above a latitude of Atlanta Georgia a very small amount of vitamin D production begins to occur around March 1. The information regarding Pennsylvania is related to our data. Significant vitamin D production in the skin begins in April and ends in September at these latitudes.

  • admin said,

    Dear Dan,
    It is very unusual but theoretically possible not to be able to make vitamin D from sun exposure. Often there is another explanation. Adults who are obese or on medications affecting vitamin D metabolism often have a more difficult time in raising their blood level of vitamin D when exposed to sun light. They often also need higher doses of vitamin D supplementation.

  • admin said,

    Dear Joan,
    Vitamin D is equally absorbed in capsule and pill form. The only time that there may be a difference if if the patient has some type of fat malabsorption syndrome such as inflammatory bowel disease.

  • mike said,

    Dr. Hollick,
    I wanted to copy you a letter I sent to Sperti to hopefully prevent what happened to me.
    Hello,
    I wanted to share my experience with your Vitamin D lamp so that you could take a look at your usage guidelines. I am a skin type 2 with no prior skin problems or burning problems with tanning in the sun. I also used a tanning bed once for 5 minutes with no problems. Two weeks prior to using your lamp, I sunbathed in Florida in January for 20 minutes a day without sunscreen with no problems.
    I followed the directions of using it no more than every other day starting at 3 minutes at 15 inches. I alternated my back and front torso. On the 2nd week, I went to 4 minutes and did not notice any redness or pain. For the first two weeks, I had no problems. I no longer had vitamin D deficiency symptoms.
    On the 3rd week, I went to 5 minutes and burned my back. My lower back was burned and my upper back had painful 1st degree burns. So, on my next session, since I had no prior problems with 4 minutes, I limited my front to 4 minutes and sunburned it as well. Also, I ended up with a burn line across my stomach.
    Since I couldn’t expose these areas and was hesitant after being burned, I started on my front legs at 3 minutes. After two sessions at 3 minutes, my legs lightly burned so I had to stop altogether.
    After a month, I still have skin rashes that flare up on my upper back. My stomach area still has light redness and a darker burn line across it.
    For safety reasons, if people can purchase this lamp without a doctor’s supervision, the guidelines should be modified to prevent what happened to me. Every other day may be too much. Three times week may be better. Having people start at one minute and using it for two weeks 3 times a week and then going up a minute may be more safe. Also, recommending staying at 3 minutes may be best if people see improvement.
    Another recommendation may be to have guidelines on maximum times based upon skin type. Also, give approximate vitamin production for every minute used to give people information on exposing themselves as little as possible to meet their goals.

  • admin said,

    Dear Mike,
    I recommend that my patients use the Sperti lamp 2-3 times a week not every day. Everybody’s skin sensitivity is different to both sunlight and the Sperti lamp. Usually following the manufacturer’s directions will not result in a sunburn.

  • mike said,

    Dr. Holick,
    In your book, you say clouds reduce UV light by 50-75%. Is it still worthwhile to get exposure during cloudy days? Would you get at least 500 IU’s during these days if you followed your sun exposure tables? Even on cloudy days, I see the EPA sometimes gives a 3-4 moderate rating of UV rays. These ratings matter as far as vitamin D production?

  • admin said,

    Dear Mike,
    Yes, you will make vitamin D on a cloudy day. The amount obviously depends on the degree and thickness of the cloud cover.

  • eliot said,

    Request for clarification on the tables in your book. You list safe minutes of sun exposure. However, you don’t specify if this is total per day, per week, what? How does it relate to the 25-50% of 1 MED, 2-3 times/week?

  • Maureen McKenna said,

    After four mega doses of Vit D my level was 162 (60-160)
    After six months of taking 1000 per day, then 2000 per day it is down to 77. So disappointed. It’s winter here in Australia and I have never felt right for 12 months. Muscle fatigue, breathless and now, for first time in my life, BP of 190! Doctors can’t find out what’s wrong. Any help please. We are not allowed to by a Vit D lamp over here because we might die of skin cancer. Seems OK to die of Vit. D deficiency though!

  • admin said,

    Dear Maureen,
    A blood level of 25-hydroxyvitamin D of 77 nmol/l is perfectly fine. I personally take and I also treat my patients with an equivalent of 3000 IUs of vitamin D a day. If you were to increase your vitamin D to 3000 IUs of vitamin D daily and if you are not obese i.e. BMI >30 I would expect that your blood level will rise.

  • admin said,

    Dear Elliot,
    Re: the tables in my book if you have an Iphone you can use the app dminder.info which will tell you how much vitamin D you are making based on your skin type. For example, 50% of an MED 3 times a week whole body would be equivalent to about 30,000 IUs of vitamin D.

  • mike said,

    Dr. Holick,
    The areas that I burned using the Sperti lamp (back, stomach, and upper legs) are sensitive to sunlight so I am limited on how much skin I can expose to the summer sun. I take 400 IU of vitamin D and can’t tolerate more. When your book has the tables about sufficient summer sun exposure, what vitamin D levels are you assuming? 30+? My hope is that I can at least get enough vitamin D to avoid fatigue symptoms this winter. My symptoms were gone after one month of spring sun exposure but my vitamin D was still under 20. Also, will my 2nd degree burns ever be able to tolerate sunlight and produce vitamin D?

  • admin said,

    Dear Mike,
    Normally skin heals from a second degree burn and will produce vitamin D when exposed to sunlight. You may want to use the app: dminder.info that will provide you with guidance for how much sun exposure will provide you with vitamin D.

  • Jennifer said,

    Hello Dr. Holick

    My Nephew who lives in Europe, is 12 years old/ 1,50 m / 60 kg. Past medical hx. serum iron level 27, Kyphoscoliosis w/ physical recuperation.
    Has recent labs completed w/ results of
    25-OH-vitD : 22.5 ng/mL. What treatment would you recommend?

    Another question: may he take ( as a child) vitD3 5,000 UI + Vit A + k2(as MK-7) + vit E?

    Thank you very much.

  • Michael Bravo said,

    Dr. Holick,

    Hello. I am curious what your take is on the misleading information coming from some sectors of the scientific and medical community, stating that there is no benefit from vitamin D. I personally know it has helped me in many ways. In fact, I mentioned them here years ago regarding my depression. Are you plan to contradict the false and misleading information that is coming out. I believe the press these papers are getting is misleading a public that needs to understand the decades of science that refutes this “new evidence” proving the contrary.

    Sincerely,
    Michael Bravo
    michael.j.bravo@gmail.com

  • admin said,

    Dear Jennifer,
    I recommend for children that they can take 1000 IUs daily and up to 2000 IUs daily is usually safe. A multivitamin containing vitamin D, vitamin K2 and vitamin A should be okay. This assumes that there is no more than 3500 IUs of vitamin A.

  • admin said,

    Dear Maureen,
    I would suspect that the insect repellant may have some chemicals that absorb the vitamin D producing UV rays but I would suspect that most can still get through it and into the skin to produce vitamin D.

  • Joan Savage said,

    Dr Holick,

    I’ve been reading “The Vitamin D Solution” with great enthusiasm for the number of myths it lays to rest, such as D2 versus D3, and for the much-expanded view of the metabolic processes affected by Vitamin D. Thank you!

    I have only one qualm, and it is to be clearer about the what could be a very long evolution of vitamin D ingestion as well as the photosynthesis pathway.

    Thinking of plankton-eating whales that have little UVB exposure prompts me to think of other animals, usually in polar regions, or fish, or subterranean nocturnal animals, that presumably acquire vitamin D from food, not exposure to sunlight.

    The evolutionary branching between Anapsids (reptiles) and Synapsids (presently including us) was over three hundred million years ago, but the age of fishes provides more ancient ancestors that may have ingested D2 or D3. [Did reptiles lose the ability to ingest D?] I for one would love to see some work by evolutionary geneticists on aspects of vitamin D that could shed light on the history.

  • Maureen Thompson said,

    Hello again Dr. Holick,

    Thanks for your response re the insect repellant.

    I have another question. Starting last fall, I increased my intake of Vit D from 1000iu to 4000iu day. I have osteoporosis, also when I press on my shin bone or sternum, it’s painful. That’s why I increased the D. In January I had my D level tested. It is 137ng/ml. I am shocked, it’s so high. I haven’t take Vit D or calcium since I got this result, and am wondering how long it will take to come back down. Also, when would be a good time to retest?

  • admin said,

    Dear Michael,

    I have written several reviews on this. One will be coming out in the near future. The brain has a vitamin D receptor and there is mounting evidence that improvement in vitamin D status reduces risk for depression.

  • admin said,

    Dear Joan
    I agree. It is difficult to find funding to do that type of research. We have been doing it for 30 years. We have done studies recently in bats and found that fish eating bats and vampires bats have very high circulating 25-hydroxyvitamin D levels. Also we have participated in research demonstrating that reptiles for the most part depend on sun exposure for their vitamin D requirement.

  • admin said,

    Dear Maureen,
    I would expect that it would be below 100 ng/mL. I would cut back to 2000 IUs daily.

  • Steve said,

    hello dr. Holick,

    Why is it always recommended to wear goggles when doing indoor tanning, but no one makes the same recommendation for outdoor tanning ? Is there a difference ?

  • admin said,

    Dear Steve,
    Typically a person tanning outside is not having ultraviolet light irradiating the eyes which can damage them. Wearing glasses and sunglasses protects the eyes.

  • Mina said,

    Are there any tests to check allergy against vit d supplements as I think I am allergic to supplements and my vit d levels are very low? Also, im not sure if my body has stopped producing vit d naturally from uvb rays so how do I check to confirm this?
    Should I see an endocrinologist?
    My esr was 15 and has spiralled to 26 and been like this for a year and worried that being intoxicated has caused other issues such as cancer and doctors do not understand vit d complications.
    Any help would be good.

  • Mark said,

    Dear Dr Holick,

    I have been enthralled by your lectures that could be found on Youtube and have recently purchased some D3 for my Mum, who is obese and has many health issues around joint problems, hypertension, osteoperosis, angina… all stemming from deteriorating health conditions after she suffered a work injury several decades ago. She is on many medications and struggles to lose weight, get good sleep, etc.

    Anyway, she is basically housebound 90% of the time so I figure her D levels must be very low and I was going to try supplementing her with 5,000UI daily until May when she will get chance to have her D levels checked, to see if there are any positive changes in how she feels.

    But searching around the web I came across some recent talk about how low D levels might be a ‘result of’ rather then ’cause of’ health issues and this has confused me. It it do with an article in Lancet called ‘Vitamin D: chasing a myth?’ and it cast doubt on the need for supplements. (http://www.thelancet.com/journals/landia/article/PIIS2213-8587(13)70164-5/fulltext)

    I was hoping you could give some kind of rebuttal on the doubts raised?

  • admin said,

    Dear Mina,

    There are no tests that I am aware of to check against vitamin D supplements. Sometimes my patients are allergic to the ingredients in the vitamin D supplement but not to vitamin D. Often switching to a different brand can help. However I do have a few patients that are unable to tolerate oral vitamin D. I recommend sensible sun exposure using the App dminder.info order to obtain their vitamin D by being exposed to ultraviolet radiation from a commercial source. It can be exposed to some sunlight and have your blood level for 25-hydroxyvitamin D be rechecked after about a month. It should increase demonstrating that you can make vitamin D in your skin from sun exposure.

  • admin said,

    Dear Mark,

    My colleague Dr. Grant and I responded to the lancet article which in my opinion suffered from many deficiencies and more importantly had unsubstantiated misleading information. A recent publication by Dr. Garland and colleagues reported that there was no increased risk for mortality when blood levels of 25-hydroxyvitamin D continued to increase up to 100 ng/mL. We have some recent evidence that we are publishing also supporting the concept that the publications suggesting that higher blood levels of 25-hydroxyvitamin D are associated with increased risk of cancer, cardiovascular disease and mortality did not take into account the possibility that these individuals with higher levels of 25-hydroxyvitamin D were actually being treated for vitamin D deficiency. They likely were based on our recent observations.

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