Vitamin D Insufficiency Is Associated With Diabetes Risk in Native American Children

Aims/Hypothesis. Vitamin D insufficiency has not been well studied in Native American (NA) children, who are at risk for obesity and diabetes. The authors examined vitamin D insufficiency and its association with body mass index (BMI) and insulin resistance. Methods. In a cross-section of NA children 5 to 18 years old (N = 198), anthropometrics, biomarkers of insulin resistance, and 25-hydroxy-vitamin D concentration [25(OH) vitamin D] were measured. BMI% and homeostatic model assessment of insulin resistance (HOMA-IR) were calculated. Results. Mean age was 10.8 +/- 0.3 years (mean +/- SEM). Mean serum 25(OH) vitamin D was 17.8 +/- 0.4 ng/mL and 97% had vitamin D insufficiency [25(OH) vitamin D < 30 ng/mL]. After adjusting for BMI, 25(OH) vitamin D was inversely associated with HOMA-IR (P < .0001) and several other markers of insulin resistance. Conclusions/Interpretation. Vitamin D insufficiency was nearly universal in this cohort of NA children and was associated with diabetes and vascular risk markers. Whether vitamin D supplementation can improve insulin resistance must be studied further.