The Effect of Vitamin D Supplementation on Cardiovascular Risk Factors Among Hispanics and African Americans With Type 2 Diabetes

Insufficient vitamin D levels have been found in subjects with type 2 diabetes (T2D). Similarly, a negative association between serum vitamin D levels and insulin resistance has been reported in a large sample representative of the adult US population and in subjects at risk for T2D. In addition, a strong association between hypovitaminosis D and hypertriglyceridemia has been demonstrated in studies done in US adult population.

Literature has indicated that subjects with T2D and insulin resistance (IR) are more likely to develop arteriosclerosis and all of the complications related to this condition, such as myocardial infarction and stroke.

These findings have increased the interest about the effect of vitamin D on metabolic abnormalities grouped under the term "cardiovascular disease (CVD) risk factors", which includes hypertension, dyslipidemia, obesity, glucose intolerance, inflammation and T2D which is in itself a risk factor for CVD.

Therefore, the purpose of the present pilot study will be to determine the effect of supplemental vitamin D intake (4000 IU or 6000 IU of Cholecalciferol daily for 6 months) on CVD risk markers and glycemic control; primarily lipid panel, insulin resistance, and glycosylated hemoglobin (A1C), in a sample of Hispanics and African-Americans with T2D and vitamin D insufficiency. If repletion of vitamin D level improves insulin resistance, glycemic control, inflammation, hypertension, dyslipidaemia or kidney functions, it may prevent the development of CVD events and decrease T2D complications.