The U.S. Navy Study - Calcium (as calcium carbonate 390 mg) (as calcium citrate 85 mg) (as calcium amino acid chelate 37 mg)
Supplementation of calcium has become the primary focus in both the prevention and treatment of osteoporosis. In a detailed meta-analysis, 15 double-blind trials, representing 1806 participants, demonstrated that calcium supplementation was more effective than placebo in reducing rates of bone loss after 2 or more years of treatment. The pooled difference in percentage change from baseline in the calcium group was 2.05% for total body bone density, 1.66% for the lumbar spine at 2 years,1.6% for the hip, and 1.91% for the distal radius. The relative risk of fractures of the vertebrae dropped 21%, but the relative risk for non-vertebral fractures was only 14%. In contrast to the studies with calcium supplements, the same sort of observations with dietary sources of calcium (e.g.,milk) have failed to show any association between dietary calcium and osteoporosis unless the intake of calcium is extremely low.