Calcium and phosphorus in human milk

Abstract

A comprehensive survey of studies dealing with calcium and phosphorus in breast milk, carried out over the last 50 years, shows a wide variability in the concentrations of these elements. Calcium concentrations tended to have higher variation than phosphorus concentrations. The means of calcium concentrations ranged from 84 to 462 mg/L (median 252 mg/L) and for phosphorus the mean values ranged from 17 to 278 mg/L (median 143 mg/L). The median Ca:P ratio was 1.7 (range, 0.8 to 6). Constitutional variables such as adolescence, gestation length, maternal undernutrition, maximal exercise testing, metabolic disorders (diabetes, hyperparathyroidism, familial hypophosphatemia, galactosemia), race, stage of lactation, weaning (and milk volume), sampling techniques (drip milk, fore- and hind-milk), and environmental variables such as socio-cultural diversity, smoking habit, diet, calcium and vitamin D supplementation, as well as prolonged use of medication (oral contraceptives), were critically reviewed in relation to changes in calcium and phosphorus levels in human milk. Except for teen-age motherhood and conditions such as familial hypophosphatemia and hyperparathyroidism during lactation, no single environmental or constitutional variable was found to consistently affect calcium or phosphorus concentration in breast milk. Only in cases of very low levels of calcium and phosphorus concentrations were adverse effects seen in the breast-fed babies.