Calcium and Phosphorus Requirements for Maximal Growth and Mineralization of the Rat

Abstract
This study was conducted to determine calcium and phosphorus requirements for both maximal growth and maximal mineralization under identical dietary conditions including defined levels of other minerals. A diet was fed which contained adequate amounts of vitamin D and all other essential organic nutrients and a 20% excess of the required amounts of other essential minerals. The estimates obtained for the daily calcium and phosphorus requirements of young male rats were: 22 mg calcium and 20 mg phosphorus for maximal growth, and 48 mg calcium and 34 mg phosphorus for maximal mineralization. The mineralization values are lower than the National Research Council estimate based on the same criterion. Relative to the calcium requirement, more phosphorus was required for growth (Ca/P = 1.1) than for mineralization, Ca/P = 1.4. A moderate reduction of the Ca/P ratio caused a slight increase in the estimates of calcium requirements for growth and mineralization.