The effect of combined magnesium and vitamin D supplementation on vitamin D status, systemic inflammation, and blood pressure: A randomized double-blinded controlled trial

Poor vitamin D and magnesium status is observed in individuals who are overweight and obese (Owt/Ob) and is often associated with a heightened risk of cardiovascular disease. Magnesium is a cofactor that assists vitamin D metabolism. We aimed to determine the efficacy of a combined magnesium and vitamin D regimen compared with vitamin D only on increasing serum 25-hydroxyvitamin D (25OHD) concentrations and the effects of these supplements on cardiometabolic outcomes.This 12-week double-blinded randomized controlled trial had three treatment arms: magnesium + vitamin D (MagD; 360 mg magnesium glycinate + 1000 IU vitamin D 3 × daily), vitamin D only (VitD; 1000 IU vitamin D 3 × daily), and placebo. A total of 95 Owt/Ob participants were randomized into one of these three study arms. Anthropometry, dietary intake, concentrations of serum 25OHD, serum parathyroid hormone (PTH), serum inflammatory markers, and blood pressure were obtained at baseline and week 12.The MagD group experienced the greatest increase in serum 25OHD concentrations (6.3 ± 8.36 ng/mL; P < 0.05). There was a decrease in systolic blood pressure (7.5 ± 8.26 mmHg; P < 0.05) for individuals who had a baseline systolic blood pressure of >132 mmHg in the MagD group. There were no statistically significant treatment effects on serum PTH concentrations and markers of inflammation.A combined MagD treatment may be more effective in increasing serum 25OHD concentrations compared with VitD supplementation alone in Owt/Ob individuals.