Vitamin D and calcium may lower diabetes risk

NEW YORK (Reuters Health) – Women with high intakes of
vitamin D and calcium appear to have a lower risk of developing
type 2 diabetes, according to Boston-based researchers.

Dr. Anastassios G. Pittas, of Tufts-New England Medical
Center and colleagues looked at data on 83,779 women enrolled
in the Nurses’ Health Study. The women had no history of
diabetes, cardiovascular disease or cancer when they enrolled
in the study. Vitamin D and calcium intake from foods and from
supplements were evaluated every 2 to 4 years.

A total of 4843 new cases of diabetes were documented over
20 years of follow-up.

“Based on the latest guidelines set by the Institute of
Medicine, only 3% of women in our cohort had adequate vitamin D
intake, and only 24% had adequate calcium intake,” Pittas’s
group reports in the medical journal Diabetes Care.

Total vitamin D intake was not significantly associated
with type 2 diabetes, but there was a difference when it came
to vitamin D supplements. The 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.

The researchers say their findings could have “important
public health implications,” because interventions to raise
both vitamin D and calcium intake “can be implemented easily
and inexpensively to prevent type 2 diabetes.”

SOURCE: Diabetes Care, March 2006.