The effect of dietary calcium supplementation on serum calcium, phosphorus, and alkaline phosphatase concentrations in a rural black population

In a rural community, where low calcium intakes and a high prevalence of hypocalcemia elevated alkaline phosphatase values and hypocalciuria had previously been documented, two groups of 30 black school children were supplemented with calcium (500 mg/day) or a placebo for a period of 3 months. No change in serum calcium or alkaline phosphatase values occurred in the placebo group, while a significant rise in mean serum calcium and fall in mean alkaline phosphatase concentrations was found in the calcium-supplemented group over the 3-month trial. No difference in growth velocities in the two groups of children was noted over the period. These results suggest that the prevalence of biochemical abnormalities in the rural population is related to a low dietary calcium intake which can be corrected by a supplement of oral calcium only.