African American females: a potential link between vitamin d insufficiency and type-2 diabetes

African American females are a high-risk population for both vitamin D insufficiency and type-2 diabetes. Numerous comparison studies have been conducted between African Americans and other racial groups, regarding vitamin D insufficiency and type 2-diabetes. African Americans, especially African American females, are at a higher risk for becoming insufficient in vitamin D when compared to other ethnic groups. The prevalence of hypovitaminosis D among African American women is ten times higher than white women. In addition, African Americans, especially African American females, have a higher prevalence of type-2 diabetes. African American females surpass white females with 100% prevalence. Although many factors may contribute to the onset of type-2 diabetes, serum 25-hydroxyvitamin D concentrations have been found to have a positive association with insulin sensitivity. In this article, we review the effects of diet and subcutaneous vitamin D synthesis on vitamin D status as well as type-2 diabetes prevalence in the most vulnerable population of both conditions, African American females. We further focus on the mechanistic studies in cell cultures and animal models, as well as cohort, intervention, and clinical studies in human subjects. In conclusion, development of vitamin D assessment in the prevention of type-2 diabetes for African American females may provide further insight for intervention and education. Adequate vitamin D intake should be promoted and recommended to decrease disparities within this population.