Calcium supplementation and bone mineral accretion in adolescent girls: an 18-mo randomized controlled trial with 2-y follow-up.
The risk of osteoporosis could be reduced by increasing bone mass or decreasing the rate of bone loss with aging. Calcium supplementation of the diet can be led to greater bone mass and this can reduce the risk of fracture in later life. A recent meta-analysis case some doubt as to whether girls (mean age 12 years) with low calcium intake (mean intake 636mg/day) benefited from taking a calcium supplement. The study was an 18-month randomized trial of calcium supplementation (providing 792 mg/day) with follow up 2 years after supplement withdrawal. The main outcome measure was change in total body, lumbar spine, and total hip bone mineral content (BMC) during supplementation and 2 years after supplement withdrawal. In this study, the supplemented group showed significantly greater gains in BMC over the 18-month study period. BMD change was significantly greater for all skeletal sites. Supplementation had most marked effects on rates on bone mass accretion during the first 6-12 months. In the 2 years after withdrawal of the supplement, skeletal gains were no longer evident. The authors conclude” calcium supplementation enhances bone mineral accrual in teenage girls, but the effect is short-lived. The likely mechanism for the effect of calcium is suppression bone turnover, which is reversed upon supplement withdrawal”.


[Lambert HL et al. Am J Clin Nutr 2008; 87:455-462