Lack of benefit from calcium supplements in young girls

A recent review of the medical literature concluded that calcium supplementation is unlikely to reduce the risk of fracture, either in childhood or later life.

Now, researchers from the University of Sheffield in the UK take another look at the effects of calcium supplementation on bone growth in adolescent girls.

First, the details.

• 96 girls (average age 12 years) with low calcium intake were randomly assigned to calcium supplementation (792 mg/day) or no calcium supplementation for 18 months.
• They were then monitored for 24 months for a total of 42 months.

And, the results.

• The average additional calcium intake in the supplemented group was 555 mg/day — significantly greater than in the control.
• Those who took the calcium supplements had significantly greater gains in bone mineral content (except at the total hip site) and bone mineral density during treatment.
• But after 42 months, these gains were no longer evident, and there was no difference between those who took the calcium supplements and those who did not.

The bottom line?
The authors concluded, “Calcium supplementation enhances bone mineral accrual in teenage girls, but the effect is short-lived. The likely mechanism for the effect of the calcium is suppression of bone turnover, which is reversed upon supplement withdrawal.”

2/24/08 19:38 JR