[Causes of phosphate deficiency syndromes and calcification disorders in premature infants fed human milk]

Premature infants fed human milk frequently show biochemical signs of phosphate depletion syndrome and bone undermineralisation. In order to explain those findings we calculated calcium- and phosphorus intake, -retention and -distribution in the body of premature infants and compared it to calcium- and phosphorus-gain and -distribution in the body of the fetus. The premature infants retained markedly less calcium and phosphorus than the fetus. Compared with the fetus premature infants utilized a higher percentage of retained phosphorus for formation of new body cell mass. Therefore, only a small amount of phosphorus was available for bone mineralisation. The calcium: phosphorus ratio in human milk is about 2:1 (mg:mg). Calcium is almost exclusively utilized for skeletal mineralisation and is deposited in bone in a 2,16:1 (mg:mg) ratio with phosphorus. Because of insufficient phosphorus supply for skeletal mineralisation, only part of the calcium provided with human milk could be utilized by the premature infants. In order to avoid disturbances of calcium-, phosphorus- and bone metabolism premature infants fed human milk need calcium and phosphorus supplementation.