title: Prevention of postnatal bone demineralization in very low-birth-weight infants by individually monitored supplementation with calcium and phosphorus.
abstract: Preterm infants are more prone to bone mineral deficiency the lower their birth weight. To achieve the intrauterine bone mineral accretion rate postnatally, 74 low-birth-weight infants (median birth weight, 980 g; range 430-1.580 g) were each supplemented enterally and/or parenterally with calcium and/or phosphorus in gradually increased amounts. The aim was to yield a simultaneous urinary excretion of Ca and inorganic phosphorus (Pi) at low concentrations (1-2 mmol/L) in spot urine specimens taken twice weekly. The hypothesis was that the intrauterine mineralization rate (4.5 mg cm-1/100 g weight gain) would be achieved postnatally in very low-birth-weight infants, if they were supplemented with enough Ca and/or Pi to effect at least a low (1-2 mmol/L) simultaneous urinary excretion of both ions, as compared with infants who do not excrete both ions and would accrete the bone minerals at a lower rate. The change in bone mineral content was measured by single photonabsorption densitometry and related to weight gain during periods of 2 to 6 wk. Infants who simultaneously excreted Ca (> 1.2 mmol/L) + Pi (> 0.4 mmol/L) in more than half of the urine samples retrospectively showed the highest bone mineral accretion, 5.1 mg cm-1/100 g weight gain, which was equivalent to the fetal mineralization rate (4.5). In this group the bone mineral status significantly contributed to the variance of the bone mineral accretion rate; severely demineralized infants showed a catch-up mineralization. A significantly lower rate (2.4) was observed in infants who excreted Ca+Pi in less than half of the urinary samples.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Neonatology and Pediatric Critical Care Medicine, Children's Hospital, University of Ulm, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Pohlandt
mesh_terms: D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000378:metabolism; D002113:Calcification, Physiologic / Q000187:drug effects; D002118:Calcium / Q000652:urine; D002136:Calcium, Dietary / Q000008:administration & dosage*; D005333:Fetus / Q000378:metabolism; D006801:Humans; D007225:Infant Food / Q000032:analysis; D007230:Infant, Low Birth Weight / Q000378:metabolism*; D007231:Infant, Newborn; D007234:Infant, Premature; D008895:Milk, Human / Q000737:chemistry; D008903:Minerals / Q000378:metabolism; D010758:Phosphorus / Q000652:urine; D016226:Phosphorus, Dietary / Q000008:administration & dosage*
chemical_list: D002136:Calcium, Dietary; D008903:Minerals; D016226:Phosphorus, Dietary; D010758:Phosphorus; D002118:Calcium