EFFECTS OF CALCIUM-VITAMIN D CO-SUPPLEMENTATION ON METABOLIC PROFILES IN VITAMIN D INSUFFICIENT PEOPLE WITH TYPE 2 DIABETES: A RANDOMIZED CONTROLLED CLINICAL TRIAL

To the best of our knowledge, no study has examined the effects of vitamin D-calcium co-supplementation on glycemic status and lipid profiles of vitamin D insufficient people with diabetes. This study was performed to assess the effects of vitamin D and calcium supplementation on metabolic profiles of vitamin D insufficient persons with type 2 diabetes. In a randomized placebo controlled clinical trial, a total of 118 persons with vitamin D insufficiency and type 2 diabetes were enrolled. Subjects were randomly assigned into four groups receiving: 1) 50000 IU/wk vitamin D+calcium placebo; 2) 1000 mg/d calcium +vitamin D placebo; 3) 50000 IU/wk vitamin D+1000 mg/d calcium; 4) vitamin D placebo +calcium placebo for 8 weeks. All participants provided three days of dietary records and three days of physical activity records throughout the intervention. Blood samples were taken to quantify metabolic profile sat study baseline and after 8 weeks of intervention. Calcium-vitamin D co-supplementation resulted in reduced serum insulin (-14.8±3.9 pmol/L, P=0.01), HbA1c (-0.70±0.19%, P=0.02), HOMA-IR(-0.46±0.20, P=0.001), LDL-(-10.3±0.1 mmol/L, P=0.04) and total/HDL-cholesterol levels (-0.91±0.16, P=0.03) compared with other groups. We found a significant increase in QUICKI index (0.02±0.01, P=0.004), HOMA-B (11.8±12.17, P=0.001) and HDL-cholesterol (0.46±0.05 mmol/L, P=0.03) levels in calcium-vitamin D group compared with others. Vitamin D supplementation led to a significant improvement in all biomarkers of glycemic status, except for fasting plasma glucose, compared with no-vitamin D group. Joint calcium-vitamin D supplementation might improve glycemic status and lipid profiles in vitamin D insufficient people with type 2 diabetes.