ABSTRACT
This chapter describes the effects of magnesium, zinc, and fluoride on calcium metabolism. A great deal of emphasis is being placed on the relationship between the intake of calcium and phosphorus, particularly with regard to the effect of the dietary Ca/P ratio because of the alleged undesirable effects of dietary phosphorus on calcium metabolism and on bone. Experimental studies in animals have shown that magnesium has an adverse effect on calcium metabolism. When fluoride was added to the constant diet as sodium fluoride and the fluoride intake was increased approximately ten-fold, the primary effect of fluoride on calcium metabolism was a decrease in urinary calcium while there was no change of the fecal calcium. The primary effect of the high phosphorus intake is a decrease in urinary calcium, while there is no significant change of other parameters of calcium metabolism, such as the intestinal absorption of calcium.
