Vitamin D Deters Diabetes?

Diabetes in adulthood might be prevented by taking vitamin D as a young adult

/ Author:  / Reviewed by: Chris Galloway, M.D.

(RxWiki News) Vitamin D—the sunshine vitamin—has been shown to protect against weak bones, heart disease, asthma and other health problems. Now it may also help ward off diabetes.

Scientists have recently discovered that taking adequate levels of vitamin D during young adulthood could reduce the risk of adult diabetes by as much as 50 percent.

"Ask a pharmacist about vitamin D supplements."

Kassandra Munger, ScD, research associate in the Department of Nutrition at Harvard School of Public Health (HSPH) in Boston, led the study, which based its findings on blood samples from United States military personnel.

Dr. Munger and her colleagues identified 310 individuals diagnosed with type 1 diabetes. They examined blood samples from these subjects taken before onset of the disease. They compared the samples with those of 613 people in a control group.

Investigators observed that healthy young adults with higher serum levels (greater than 75 nanomoles per liter) of vitamin D had about half the risk of developing type 1 diabetes than those with the lowest levels of vitamin D (less than 75 nanomoles per liter). The authors commented that most of subjects were white and non-Hispanic.

Type 1 diabetes is a lifelong (chronic) disease in which there are high levels of sugar (glucose) in the blood. Because type 1 diabetes is most often diagnosed in children, adolescents or young adults, it is often called juvenile-onset diabetes. Type 2 diabetes is commonly called adult-onset diabetes.

With type 1 diabetes, the body’s immune system attacks and permanently disables the insulin-making cells in the pancreas. About 5 percent of the estimated 25.8 million people in the US with diabetes have type 1, according to the American Diabetes Association. Although it often starts in childhood, about 60 percent of type 1 diabetes cases occur after age 20.

An estimated 1 billion people worldwide have inadequate levels of vitamin D in their blood, and deficiencies can be found in all ethnicities and age groups, according to a statement from HSPH.

HSPH says that sun exposure is an excellent source of vitamin D, but sunscreen, clothing, skin pigmentation and winter months reduce its production. Food tends to be a poor source of vitamin D, with “good” sources, such as salmon and fortified milk, containing 400 IU [international units] or less per serving.

“Whereas it is premature to recommend universal use of vitamin D supplements for prevention of type 1 diabetes, the possibility that many cases could be prevented by supplementation with 1,000 to 4,000 IU/day, which is largely considered safe, is enticing,” the authors said.

Alberto Ascherio, MD, professor of epidemiology and nutrition at HSPH and the study’s senior author, added, “The risk of type 1 diabetes appears to be increased even at vitamin D levels that are commonly regarded as normal, suggesting that a substantial proportion of the population could benefit from increased vitamin D intake.”

The study was published online on February 3 in the American Journal of Epidemiology and will appear in the March 1 print edition. The study was funded by the National Institute of Neurological Disorders and Stroke.

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Review Date: 
February 8, 2013
Last Updated:
February 10, 2013