AUCKLAND, New Zealand—According to the results from a recent study at the University of Auckland, 1,200 mg/d of calcium has effects on bone mineral density (BMD) in men comparable with those found in postmenopausal women, but a dosage of 600 mg/d is ineffective for treating BMD (Arch Intern Med. 2008;168(20):2276-2282). Researchers conducted a double blind, controlled trial for a two-year period in 323 healthy men at least 40 years old (mean age, 57 years) recruited by a newspaper advertisement. Subjects were randomized to receive 600 mg/d of calcium, 1,200 mg/d calcium or placebo.
The BMD increased at all sites in the group receiving calcium, 1,200 mg/d, by 1 percent to 1.5 percent more than those receiving placebo. The results for the group receiving 600 mg/d of calcium were not different from the placebo group at any BMD site. There was no interaction between the BMD-treatment effect and either age or dietary calcium intake. There were dosage-related, sustained decreases in serum parathyroid hormone (P<0.001), total alkaline phosphatase activity (P=0.01), and procollagen type 1 N-terminal propeptide (P<0 .001) amounting to 25 percent, 8 percent and 20 percent, respectively, in the group receiving 1,200 mg/d of calcium at two years. Tooth loss, constipation and cramps were unaffected by calcium supplementation, falls tended to be less frequent in the group receiving 1,200 mg/d, but vascular events tended to be more common in the groups receiving calcium versus the group receiving placebo.
