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

Diabetes and Vitamin D

Posted by admin on November 27, 2008 under Diabetes, Vitamin D | 6 Comments to Read

Diabetes mellitus type I

Studies in mice have suggested that pretreating mice that are prone to developing type I diabetes with the active form of vitamin D (1,25-hydroxyvitamin D [1,25(OH)2D]) reduces the development of type I diabetes by 80%.  This study is supported by the observation in Finland where children in the 1960’s routinely received 2,000 IU of vitamin D a day during their first year of life.  When these children were followed for the next 31 years, it was observed that these children had a reduced risk of developing type I diabetes by 78%.  Children who were vitamin D deficient at the same time and also followed for 31 years had an almost 300% increased risk of developing type I diabetes.  


Hypponen E, Laara E, Jarvelin M-R, Virtanen SM.  Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study.  Lancet 2001;358:1500-1503.

Diabetes mellitus type II

The beta islet cells that produce insulin in the pancreas have a vitamin D receptor.  The active form of vitamin D stimulates the pancreas to produce insulin.  It has been observed that the relative risk of developing type II diabetes is reduced by as much as 33% in men and women who increase their intake of vitamin D above 800 IU/day along with 1,000 milligrams of calcium.  


Pittas AG, Dawson-Hughes B, Li T, et al.  Vitamin D and calcium intake in relation to type 2 diabetes in women.  Diabetes Care 2006:29:650-56.

  • Brian said,

    I have heard of studies where Diabetes is more prevalent in people living at lower altitudes – do people at higher elevations have higher Vitamin D production because there is less atmosphere to block the sun’s rays?

  • Craig said,

    It is true that more UVB rays are able to penetrate the thinner atmosphere of higher elevations. People living at higher altitudes also tend to have higher vitamin D levels. It makes sense that they’d also have a reduced risk of diabetes.

  • admin said,

    Dear Craig,
    The UVB rays are absorbed by the ozone layer. Therefore the higher the altitude there is less ozone for the UVB rays to travel through and therefore more vitamin D is made living at higher altitudes. We conducted a study in India and showed that in November at the Taj Mahal very little vitamin D was made whereas at the same latitude but at 5000 feet elevation at base camp on Mount Everest vitamin D was efficiently made.

  • admin said,

    Dear Craig, you are correct. The higher the altitude the more efficient the sun is in producing vitamin D.

  • Lizzie King said,

    Dear Dr Hollick,
    I am finishing my studies at The Institute for Integrative Nutrition. I will be stating a baby food business when I have graduated, and having listened to your Vitamin D class I would love some advice. I will be supplementing my fresh, frozen baby food with both omega 3 and Vitamin D as I think this is where infants upon weaning are most likely to be deficient. I would therefore love to know your advice on how much an infant of 6months-12 months should be receiving. I was thinking about 300-400 IU per day? And also, in what form this would be most stable if the food was to be heated up.

    Thanks so much,


  • admin said,

    Dear Lizzie,
    The Institute of Medicine and the American Academy of Pediatrics and the Endocrine Society recommend that during the first year of life infants should receive 400 IUs of vitamin D daily. Vitamin D is very stable to heat up to approximately 300°F.

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