Vitamin D May Reduce Women's Risk Of Diabetes

Women with high intakes of vitamin D and calcium appear to have a lower risk of developing Type II diabetes, according to a study conducted by Boston-based researchers and published in the March issue Diabetes Care (29:650-56, 2006).

Researchers studied 83,779 women enrolled in the Nurses' Health Study that did not have a history of diabetes, cardiovascular disease or cancer at the onset of the study.

Vitamin D and calcium intake from foods and supplements were evaluated every two to four years. A total of 4,843 new cases of diabetes were documented over 20 years of follow-up.

According to the study results, and based on the latest guidelines set by the Institute of Medicine, only 3 percent of the participants had adequate vitamin D intake, and only 24 percent had adequate calcium intake. Total vitamin D intake was not significantly associated with Type II diabetes, but there was a difference when it came to vitamin D supplements. The research team saw a 13 percent lower risk of diabetes among women in the highest versus the lowest category of vitamin D intake from supplements.

Women with the highest total calcium intake had a 21 percent lower risk of diabetes than those with the lowest intake. In this case, the source of calcium didn't make much difference: the risk was 18 percent lower among women in the highest versus the lowest category of calcium intake from supplements.

Overall, the lowest risk of diabetes was observed among women with the highest combined intakes of calcium and vitamin D compared with those with the lowest.

Researchers concluded the results of this large prospective study suggest a potential beneficial role for both vitamin D and calcium intake in reducing the risk of Type II diabetes.