A Study of the Magnesium Needs of Preschool Children

Abstract

In an attempt to determine the amount of magnesium needed by growing children, thirty-three balance studies have been made with children between 4 and 7 years of age receiving various levels of magnesium. Calcium and phosphorus balance studies were made simultaneously in order to determine to what extent these may have influenced the magnesium retentions. In the study, the influence of insufficient vitamin D and vitamin C was seemingly ruled out since the children received a constant and what was believed to be an adequate amount of vitamin D obtained from cod liver oil and viosterol, and vitamin C from canned tomato and orange juice given twice daily. Magnesium retentions, which varied from 0.4 mg. to 3.1 mg. per kilogram, were considered in relation to ingestion, urinary magnesium, and the influence of the calcium: magnesium ingestion ratios. There was no evidence that the magnesium retentions were influenced by the calcium ingestions, nor was there seemingly any relation between the magnesium retentions and calcium retentions. Calcium: magnesium ingestion ratios ranged between 2.8 and 6.7, whereas calcium: magnesium retention ratios were between 3.8 and 30.3. The magnesium of the urine, which tended to parallel the magnesium ingestion suggested that this might be used as a means of determining the sufficiency of the diet in this respect. Low urinary magnesiums when co-existent with low retentions were indicative of too low ingestions. High urinary magnesiums with low retentions were interpreted as indicating that enough had been fed and that previously the individual had been receiving a diet containing a sufficient amount, whereas high urinary magnesiums with high retentions following high ingestions indicated that the individual had been receiving previously less than the optimum amount. Seventy-five per cent of the children studied were in this group. It was concluded tentatively that diets of children of the ages studied should contain not less than 13 mg. per kilogram of body weight. Further studies with different types of diets are needed to confirm these findings.