Longitudinal development and tracking of calcium and dairy intake from teenager to adult.

OBJECTIVES

Because of growing interest in the potential role of calcium in preventive pediatric strategies against osteoporosis, the longitudinal development and tracking of calcium had a dairy intake from adolescence into adulthood was addressed.

DESIGN

In the Amsterdam Growth and Health Study, a group of 84 males and 98 females were followed over a 15 y period from age 13-27 y. The calcium and dairy intake was assessed six times by a cross-check dietary history method. To assess tracking, two traditional approaches, interperiod correlation coefficients and percent of subjects who remained in the same quartile of calcium intake over time, and a new approach based on generalized estimating equations were used.

RESULTS

The mean calcium intake was relatively high and increased over time (30%). The tracking of calcium and dairy intake from adolescence into adulthood was moderate in both sexes (for example the correlation for calcium was 0.43 in males and 0.38 in females).

CONCLUSIONS

The predictability of calcium intake over time does not seem to be sufficiently strong to identify teenagers who are likely to maintain an inadequate calcium intake in adulthood. Therefore, the identification and treatment of subjects with a low calcium intake cannot be limited to the teenage period but should be extended into adulthood.