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

Dr. Holick’s Responses to Participant Questions During the December 5, 2008 Live Webinar Presentation “Vitamin D & Chronic Disease Risk”

Posted by mfholick on March 6, 2009 under Cancer, Multiple Sclerosis, Osteomalacia, Osteoporosis, Rickets, Vitamin D | 62 Comments to Read





I have heard that vitamin D may play a role in epilepsy, possibly due to interaction with anti-epileptic drugs.  Is this becoming an acknowledged effect?  And how much vitamin D is necessary to combat the interaction to reduce seizures?

Response:  Epileptic drugs will enhance the destruction of vitamin D making patients who are on anti-seizure medications at higher risk for developing vitamin D deficiency and osteomalacia or rickets.  Measurement of 25-hydroxyvitamin D [25(OH)D] is important in patients on antiepileptic medications.  Often twice as much vitamin D is required to maintain a blood level of  25(OH)D of > 30 ng/ml.  Thus, 2,000-4,000 IU of vitamin D/d is usually needed.  An alternative is to take 50,000 IU of vitamin D2 either once every week or once every two weeks depending on the serum 25-hydroxyvitamin D level.




What is your position on vitamin D and depression and schizophrenia?

Response:  There is evidence that vitamin D deficiency during pregnancy increases the risk of the child developing schizophrenia during their adult life.  There is also evidence that vitamin D receptors exist in the brain, and that the active form of vitamin D, 1,25-dihydroxyvitamin D, Read more of this article »

Osteoporosis and Vitamin D

Posted by admin on November 27, 2008 under Osteoporosis, Vitamin D | 5 Comments to Read

Vitamin D deficiency will cause removal of both the calcium and matrix from the bone, and as a result, will cause osteopenia and can precipitate and exacerbate osteoporosis.  Unlike osteomalacia which causes bone pain, osteoporosis, which is porotic bone, i.e., holes in the bones and loss of bone does not cause bone pain unless there is an acute fracture.  Typically this pain resolves as the fracture heals and can be easily distinguished from osteomalacia.  


Bischoff-Ferrari, HA, Giovannucci, E., Willett, W.C., Dietrich, T., and Dawson-Hughes, B.  Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes.  Am J Clin Nutr  2006; 84:18-28.  

Boonen S, Bischoff-Ferrari A, Cooper C, Lips P, Ljunggren O, Meunier PJ, Reginster JY.  Addressing the musculoskeletal components of fracture risk with calcium and vitamin D:  a review of the evidence.  Calcif Tissue Int  2006; 78(5):257-70.

Chapuy MC, Arlot ME, Duboeuf F, Brun J, Crouzet B, Arnaud S, Delmas PD, Meunier PJ.  Vitamin D3 and calcium to prevent hip fractures in elderly women.  N Engl J Med 1992; 327(23):1637-1642.

A 65 year old female with osteopenia

Posted by admin on November 26, 2008 under Case Files | 3 Comments to Read

I was referred a 65 year old white female who on bone mineral density analysis was found to be osteopenic and had a history of 2” height loss.  She entered menarche at the age of 13 and had regular periods until menopause at the age of 52.  She was on hormone replacement therapy and developed breast cancer at the age of 61.  She underwent lumpectomy and radiation therapy, and initially was put on tamoxifen and placed on an aromatase inhibitor for the past four years.  She has limited her calcium intake because of concerns about vascular calcification and kidney stones.  There was no previous history of premature graying (which can increase risk of having osteopenia and osteoporosis) nor was there a history of kidney stones.   Read more of this article »

Welcome to VitaminDHealth.org

Posted by mfholick on 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.

Read more of this article »