Calcium plus vitamin D supplementation influences biomarkers of inflammation and oxidative stress in overweight and vitamin D-deficient women with polycystic ovary syndrome: A randomized double-blind placebo-controlled clinical trial

Abstract

Objective This study was conducted to determine the effects of calcium plus vitamin D supplementation on inflammatory factors and biomarkers of oxidative stress among overweight vitamin D-deficient women with polycystic ovary syndrome (PCOS). Design, Patients and Measurements This randomized double-blind placebo-controlled clinical trial was performed among 104 overweight vitamin D-deficient women diagnosed with PCOS aged 18-40 years. Participants were randomly divided into four groups. Group A received 1000 mg calcium daily and vitamin D placebo weekly (N = 26), group B 50000 IU vitamin D weekly and calcium placebo daily (N = 26), group C 1000 mg calcium daily plus 50000 IU vitamin D weekly (N = 26) and group D calcium placebo daily plus vitamin D placebo weekly (N = 26) for 8 weeks. Fasting blood samples were taken at baseline and 8 weeks after intervention to measure inflammatory factors and biomarkers of oxidative stress. Results After 8 weeks, individuals taking calcium plus vitamin D supplements had greater decreases in homoeostatic model assessment beta-cell function (HOMA-B) score (-11·1 vs -8·6, -3·4 and 13·7, respectively, P = 0·03), serum high-sensitivity C-reactive protein (hs-CRP) (-948·3 vs 802·3, -383·8 and 618·2 ng/ml, respectively, P = 0·04) and plasma malondialdehyde (MDA) concentrations (-0·6 vs -0·5, -0·1 and 0·6 μmol/l, respectively, P = 0·009), and significant increases in plasma total antioxidant capacity (TAC) (35·2 vs 21·1, 22·5 and -153·8 mmol/l, respectively, P = 0·006) and glutathione (GSH) levels (216·0 vs 3·9, -47·5 and -160·8 μmol/l, respectively, P = 0·001) compared with calcium alone, vitamin D alone and placebo groups. Calcium plus vitamin D cosupplementation did not influence plasma NO and catalase levels. Conclusions We found that calcium plus vitamin D cosupplementation for 8 weeks among overweight and vitamin D-deficient women with PCOS had beneficial effects on inflammatory factor and biomarkers of oxidative stress.