Dietary calcium and bone density among middle-aged and elderly women in China.

Associations between dietary calcium and bone status were investigated in 843 Chinese women aged 35-75 y who were selected from five rural counties where dietary calcium varied considerably. Bone mineral content (BMC) and bone mineral density (BMD) at the radius were significantly higher in one of the pastoral counties with higher calcium intake than in the nonpastoral counties. Analysis by individual for all counties combined showed that BMC and BMD were correlated positively with total calcium (r = 0.27-0.38, P < 0.0001), dairy calcium (r = 0.34-0.40, P < 0.0001), and to a lesser extent with nondairy calcium (r = 0.06-0.12, P = 0.001-0.100), even after age and/or body weight were adjusted for. The results strongly indicated that dietary calcium, especially from dairy sources, increased bone mass in middle-aged and elderly women by facilitating optimal peak bone mass earlier in life.