Vitamin D deficiency was long suspected to be a risk factor for glucose intolerance and poor diabetes control. Now, there’s proof.
In one study, when non-obese mice bred to be diabetic (type 1) were given vitamin D throughout their lives, their risk of developing diabetes decreased by 80%. A quote from The American Journal of Clinical Nutrition, “This is in good agreement with the recent observation by Hypponen et al [in their study, ‘Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study’] that children receiving 2000 IU vitamin D from [their first year onward] decreased their risk of getting type 1 diabetes by 80%.”1
And it’s not just non-obese, type 1 prone persons who can benefit from greater consumption of vitamin D. According to a study published in Endocrine Society’s Journal of Clinical Endocrinology & Metabolism, people who have low levels of vitamin D are more likely to have type 2 diabetes, whether they are obese or at a normal, healthy weight. “Numerous observational studies (mostly cross-sectional, but some longitudinal) demonstrate a consistent association of low serum [vitamin D] levels with diabetes, [pre-diabetes], metabolic syndrome, obesity, and fat content (adiposity). This relationship is noted in adults and in children, in both sexes, and in various ethnic backgrounds.”2
A population-based study from Norway, published in the European Journal of Nutrition and Pediatric Diabetes, showed a similarly strong inverse association between elevated BMI (body mass index) and serum vitamin D levels. “In children and adolescents, the association seems more consistent and prominent. More than 50% of Norwegian children and adolescents with excess body weight had a low [vitamin D] status, and 19% had vitamin D deficiency.”2 Other studies have confirmed that high BMI and low vitamin D levels appear to go hand in hand. Further more, there is proof that you can decrease your chances of developing diabetes by supplementing with vitamin D, even if you are obese.
Diabetes has far-reaching consequences, beyond the pain of daily glucose testing and insulin injections. Diabetes can significantly decrease one’s quality of life as well as shorten one’s lifespan. This is, in no small part, due to secondary complications brought on by the condition. These complications include skin infections, eye problems, kidney disease and nerve damage (called neuropathy) that can develop because of diabetes.
Whose most at risk for Vitamin D deficiency?
For obvious reasons, the more melanin (the substance that determines skin color and protects against ultraviolet radiation) you have in your skin the greater your risk of vitamin D deficiency. This is especially true if you live in a region that is not sunny most of the year. And, according to the American Journal of Clinical Nutrition, there has been a resurgence in vitamin D deficiency among “neonates and young children, in part because of the campaign to encourage all women to provide all of their infants’ nutrition through breastfeeding. [There] is very little, if any, vitamin D in human milk. [And] infants, especially infants of women of color, are at high risk of developing vitamin D deficiency and rickets if they are not given a vitamin D supplement.”1
The elderly are also at greater risk of vitamin D deficiency, generally due to their decreased exposure to sunlight. The elderly, infants, young children, and anyone of any age who has a dark complexion and is not living in the sun belt is at greater risk of vitamin D deficiency than the rest of the population.
What you can do about it
Aside from soaking up as much natural sunlight as your schedule allows, you can supplement with vitamin D3. Why D3? It’s the form of vitamin D that your body produces when you are exposed to sunlight or a tanning bed. The most common form of vitamin D prescribed by doctors is D2, also known as Drisdol, which is made by irradiating fungus and plant matter. Dr. Mercola wrote an entire article about why you should avoid D2 and use D3 instead, and I’ve included the link. The most important reason to choose D3, for me, is the fact that it converts faster than D2. According to the article, “vitamin D3 is converted 500 percent faster than vitamin D2. [Also] Vitamin D2 also has a shorter shelf life, and its metabolites bind poorly with proteins, further hampering its effectiveness.”3
The research has spoken. Obesity is not the cause of diabetes in the obese, vitamin D deficiency is. In fact, a study presented at the 2015 European Congress on Obesity demonstrated that correcting vitamin D levels could help you lose weight, IF you are vitamin D deficient. This is not surprising, considering vitamin D deficiency and obesity are both widespread in the United States. But it’s comforting to know that getting more sun exposure and/or taking a vitamin D3 supplement can help prevent the development of diabetes and obesity.
I explain how to calculate the amount of vitamin D you need in the video ‘Vitamin D vs Disease‘.
1 Holick, Michael F. “Vitamin D: importance in prevention of cancers, type 1 diabetes, heart disease, and osteoporosis”. The American Journal of Clinical Nutrition, March 2004. Web. June 2016
2 CJ Rosen, JS Adams, DD Bikle, et al. “The Nonskeletal Effects of Vitamin D: An Endocrine Society Scientific Statement”. Endocrine Society’s Journal of Clinical Endocrinology & Metabolism, June 2012. Web. July 2016
3 Mercola, Joseph, MD. “If You Take Oral Vitamin D You MUST Avoid Making This Serious Mistake”. Mercola, February 23, 2013. Web. July 2016
Doheny, Kathleen. “Low Vitamin D Linked to Poor Diabetes Control”. Web MD, June 21, 2010. Web. July 2016
Mercola, Joseph, MD. “Vitamin D Can Save You from Diabetes and Dementia”. Mercola, March 9, 2015. Web. June 2016
Weil, Andrew, MD. “Vitamin D for Weight Loss?” Dr. Weil, August 3, 2015. Web. July 2016