Effects of calcium supplementation on lipids, blood pressure, and body composition in healthy older men: a randomized controlled trial.

Randomized controlled trial in generally healthy older men in Australia. Active intervention arms received calcium citrate 600 mg/day or 1200 mg/day for 2 years; the trial ran at a tertiary medical center between April 2004 and July 2007.

Calcium citrate was given as elemental calcium 600 mg once daily in the evening (Ca600) or 600 mg twice daily for 1200 mg/day (Ca1200) for 2 years, compared with placebo.

Overall, calcium supplementation did not improve serum lipids, blood pressure, or body composition in healthy older men. The primary endpoint, change in the HDL to LDL cholesterol ratio, showed no significant treatment effect (P = 0.47), and there were no significant between-group differences for LDL, HDL, total cholesterol, HDL to total cholesterol ratio, triglycerides, blood pressure, soft tissue mass, or weight (lipids P > 0.28; blood pressure P > 0.60; fat mass P = 0.45; lean mass P = 0.33; weight P = 0.83). Post hoc subgroup analyses in men with baseline dietary calcium intake below 785 mg/d suggested lower blood pressure in the Ca1200 group versus placebo at 2 years, with systolic and diastolic changes reported as 24.2 mm Hg and 23.3 mm Hg, respectively (P = 0.05-0.06).

The main results were null, and the apparent blood pressure benefit came from post hoc subgroup analyses rather than the primary comparison. The population was limited to generally healthy older men, baseline age data by arm were not reported, and concurrent lipid-lowering or blood pressure-lowering therapy was used by some participants (n = 19 and n = 20).