Effects of protein on the calcium economy

Studies of the association of dietary protein intake and various components of the calcium economy lead to conflicting conclusions, some suggesting that protein would negatively affect calcium retention and others that it would have a positive effect. Most of the apparent conflict can be explained by two factors: (1) the interdependence of the two nutrients for bone health and (2) probable delayed adaptation to altered intake, such that short-term studies may fail to capture the steady-state relationship between protein intake and calcium balance. At the whole body level, most studies show that high protein intake is osteoprotective, but only if calcium intake is adequate; similarly, metabolic evidence indicates that the protective effect of calcium for the skeleton is evident only when protein intake is relatively high.