A study, reported in Diabetes Care (December 2004), found that, as blood levels ofvitamin D rise, the possibility of diabetes decreases in non-Hispanic Caucasians andMexican Americans—but not in African Americans. The researchers based their findingson a study of 6228 participants, representative of the US population, who took part inthe Third National Health and Nutrition Examination Survey.
The results of the study showed that Caucasians with the largest vitamin D levels hadonly one quarter the risk of having diabetes, compared with those with the lowest levels.In Mexican Americans, the comparative risk dropped even more. The researchersbelieve the reason why this pattern was not seen in African Americans is that it may"reflect decreased sensitivity to vitamin D and/or related hormones" in this group. Basedon the data, the researchers said the finding may "offer an explanation, in part, for thegenerally lower prevalence of type 2 diabetes observed in Caucasian populationsaround the world compared with other ethnicities."