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.