New research suggests that a woman’s efforts to prevent osteoporosis should actually start before puberty. In the first trial to track calcium’s effects on bone density in girls eight to 13 years old for as long as seven years, researchers at the Ohio State University Medical Center found that calcium supplementation significantly increased bone mass development during a critical childhood growth spurt. Their findings suggest that increased calcium use by pre-adolescent girls is likely to help prevent fractures and osteoporosis much later in life.

In this study, the calcium-supplemented group of 354 girls showed a faster rate of bone mass development. Researchers found the biggest difference in bone mineral density between the supplemented and non-supplemented groups occurred from one year before and one year after the onset of menstruation.

Similarly, Israeli researchers found that high calcium intakes during adolescence could increase bone mass. The study measured the effect of calcium supplementation on bone mass in 100 adolescent girls (average age of 14) with low calcium intakes. During the 12-month study, the treatment group received 1,000 mg of elemental calcium daily.

The researchers found the calcium-supplemented group had greater total-body and lumbar spine bone mineral density. Calcium supplementation also significantly decreased bone turnover, a risk factor for osteoporosis.

Sources: Am J Clin Nutr. 2003 Nov;78(5):993-8; Am J Clin Nutr. 2005 Jan; 81(1):175-188