Low vitamin D levels may raise risk of Type 1 diabetes
Washington, February 5 : Having adequate levels of vitamin D during young adulthood may nearly halve the risk of adult-onset type 1 diabetes, according to researchers at Harvard School of Public Health (HSPH).
"It is surprising that a serious disease such as type 1 diabetes could perhaps be prevented by a simple and safe intervention," said lead author Kassandra Munger, research associate in the Department of Nutrition at Harvard School of Public Health.
In type 1 diabetes (once called juvenile-onset or insulin-dependent diabetes), the body's immune system attacks and permanently disables the insulin-making cells in the pancreas.
The researchers conducted a prospective case-control study of U.S. military personnel on active duty, using blood samples from the Department of Defense Serum Repository, which contains more than 40 million samples collected from 8 million military personnel since the mid-1980s. Identifying 310 individuals diagnosed with type 1 diabetes between 1997 and 2009, the team examined blood samples taken before onset of the disease, and compared the samples with those of 613 people in a control group.
The researchers found that white, non-Hispanic, healthy young adults with higher serum levels (>75 nmol/L) of vitamin D had about half the risk of developing type 1 diabetes than those with the lowest levels of vitamin D (<75 nmol/L). Although the researchers found no significant association among Hispanics and blacks, the authors said this may be due to the small number of individuals in these groups.
"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," said Alberto Ascherio, professor of epidemiology and nutrition at HSPH, the study's senior author.
The study will be published in the American Journal of Epidemiology.