Vitamin D may help protect against diabetes, a major disease estimated to affect 8.3 percent of the United States population. A growing number of studies suggest that running low on vitamin D may raise your risk of diabetes. In addition, vitamin D deficiency may increase risk of heart disease and death among people who already have diabetes. However, studies have yet to show that taking vitamin D supplements can prevent or treat diabetes.
How Does Vitamin D Help Fight Diabetes?
In studies on animals and humans, scientists have found that vitamin D deficiency may contribute to insulin resistance (a key factor in the development of diabetes). Additionally, research indicates that vitamin D deficiency may be linked to abnormalities in blood sugar levels.
The Science Behind Vitamin D and Diabetes
People with lower vitamin D levels are significantly more likely to have diabetes compared to people with higher vitamin D levels, according to the National Institutes of Health. While it's possible that taking vitamin D supplements may boost your defense against diabetes, a 2011 report from the journal Current Drug Targets cautions that more research is needed before vitamin D supplements can be recommended for diabetes prevention.
In a 2010 research review published in the journal Endocrine Practice, researchers found that achieving sufficient vitamin D levels may be beneficial for people with prediabetes (a condition that affects about 79 million Americans). What's more, a 2010 study of 289 diabetes patients found that those with severe vitamin D deficiency had an increased risk of death. Published in Diabetes Care, the study found that patients with severe vitamin D deficiency were more likely to develop cardiovascular risk factors (such as high blood pressure).
Some studies also suggest that taking vitamin D in combination with calcium may help protect against diabetes. For instance, a 2007 research review from The Journal of Clinical Endocrinology and Metabolism determined that insufficient levels of vitamin D and calcium may negatively affect blood sugar control. The review's authors concluded that taking supplements containing both nutrients may improve blood sugar metabolism.
Should You Take Vitamin D Supplements to Fight Diabetes?
Although it's not known whether vitamin D supplements can aid in diabetes prevention, maintaining optimal vitamin D levels is important for overall health (especially bone health). Since it can be challenging to get your fill of vitamin D solely through food sources and sunlight exposure, many medical experts recommend boosting your vitamin D levels by taking a daily supplement.
While maintaining optimal vitamin D levels is also important for diabetes patients, using vitamin D supplements in place of standard diabetes care can have serious health consequences. If you're interested in using vitamin D supplements to help with diabetes control, talk to your doctor to determine a safe and effective dosage.
Sources:
Boucher BJ. "Vitamin D insufficiency and diabetes risks." Curr Drug Targets. 2011 Jan;12(1):61-87.
Joergensen C, Gall MA, Schmedes A, Tarnow L, Parving HH, Rossing P. "Vitamin D levels and mortality in type 2 diabetes." Diabetes Care. 2010 Oct;33(10):2238-43.
National Institutes of Health. "Vitamin D: MedlinePlus Supplements". April 2011.
Palomer X, González-Clemente JM, Blanco-Vaca F, Mauricio D. "Role of vitamin D in the pathogenesis of type 2 diabetes mellitus." Diabetes Obes Metab. 2008 Mar;10(3):185-97.
Pittas AG, Lau J, Hu FB, Dawson-Hughes B. "The role of vitamin D and calcium in type 2 diabetes. A systematic review and meta-analysis." J Clin Endocrinol Metab. 2007 Jun;92(6):2017-29.

