Vitamin D deficiency is associated with many cardiometabolic disorders, including type 2 diabetes, metabolic syndrome, hypertension, obesity and additional obesity-related chronic inflammatory diseases. However, the inconsistency among studies evaluating vitamin D metabolite levels and direct clinical markers of these conditions have been inconsistent. Therefore, a new study was performed to assess the relationship between circulating vitamin D metabolites and direct measures of glucose metabolism and insulin action in morbidly obese, adult women.