Effects of calcium and vitamin D supplementation on blood pressure and serum lipids and carotenoids: a randomized,double-blind,placebo-controlled,clinical trial

PurposeTo estimate the effects of calcium or vitamin D supplementation or a combination of both on blood pressure and serum lipid and carotenoid levels.MethodsNinety-two colorectal adenoma patients were randomized in a pilot, double-blind, placebo-controlled clinical trial of supplemental vitamin D₃ 800 IU and elemental calcium 2.0 g (as calcium carbonate) alone or in combination in divided doses twice daily with meals over 6 months.ResultsRelative to placebo, mean serum triglycerides decreased 30% (P = .10) and 32% (P = .10) in the calcium and calcium plus vitamin D₃ treatment groups, respectively. When the two calcium intervention groups were pooled and compared with the pooled noncalcium groups, the estimated supplemental calcium treatment effects were statistically significant for triglycerides (P = .04). Similar but nonstatistically significant decreases (5%–7%) were observed for serum total cholesterol levels. Mean systolic blood pressure increased 6% (P = .08) in the calcium group; otherwise, there were no appreciable changes in systolic or diastolic blood pressures in any active treatment group. Mean serum total carotenoid levels decreased 14% (P = .07) in the calcium and 9% (P = .10) in the calcium plus vitamin D₃ groups.ConclusionsOur results suggest that supplemental calcium alone or combined with vitamin D₃ but not vitamin D₃ alone may reduce serum lipids and lipophilic micronutrients.