[Phosphorus and calcium metabolism of premature infants fed human milk and formulated milk]

Abstract

Development of rickets in vitamin-D supplemented very-low-birthweight (VLBW) infants can be associated with low Phosphorus (P) and Calcium (Ca) intake. Therefore, we estimated P and Ca intake of three VLBW-infants who were fed pooled human milk after birth and then switched to an adapted formula. We measured P, Ca, activity of alkaline phosphatase and parathormone in serum and P and Ca excretion in urine. P and Ca intake was below the estimated requirement for prematures with pooled human milk as well as with the adapted formula, on the other hand, Ca and especially P intake increased when infants were switched to the adapted formula. When fed human milk we found evidence for a P deficiency in the body with signs of inadequate bone mineralisation. On the adapted formula infants showed Ca deficiency but bone mineralisation improved. From our findings we conclude that on pooled human milk VLBW-infants do not receive the required amount of P and Ca. The signs of Ca deficiency on the adapted formula might be related to low Ca intake or to the P: Ca ratio of the formula which could be inadequate for VLBW-infants.