Low serum calcium and high parathyroid hormone levels in neonates fed 'humanized' cow's milk-based formula.
We previously suggested that "late" neonatal hypocalcemia is related to a low calcium-phosphorus ratio of current cow's milk-based formula compared with human milk. However, there are no longitudinal studies of ionized calcium and parathyroid hormone concentrations in neonates receiving formulas with varying Ca/P ratios. Sixty-nine term neonates were studied through 2 weeks of age, and formula-fed neonates were randomized at birth to receive formula with molar ratios of 0.9, 1.2, or 1.4. Serum phosphate concentrations on days 2 and 6 of age were higher, and ionized calcium levels lower on days 6 and 14, in formula-fed vs human milk-fed neonates. Serum intact parathyroid hormone level increased between days 2 and 6 in formula-fed neonates compared with a decrease in human milk-fed neonates. Serum parathyroid hormone level on day 6 correlated with phosphorus intake among formula-fed neonates. No differences were noted in serum mineral or hormone levels among formula-fed groups. We speculate that the lowering of serum ionized calcium concentrations in neonates fed a modern "humanized" cow's milk formula may be a factor in late neonatal hypocalcemia.
Specker
B L
BL
Department of Pediatrics, University of Cincinnati Medical Center, OH 45267-0541.
Tsang
R C
RC
Ho
M L
ML
Landi
T M
TM
Gratton
T L
TL
D000704:Analysis of Variance; D002118:Calcium / Q000097:blood*; D006801:Humans; D006996:Hypocalcemia / Q000209:etiology; D007225:Infant Food / Q000009:adverse effects*; D007231:Infant, Newborn; D008895:Milk, Human; D010281:Parathyroid Hormone / Q000097:blood*; D010710:Phosphates / Q000097:blood; D010758:Phosphorus
D010281:Parathyroid Hormone; D010710:Phosphates; D010758:Phosphorus; D002118:Calcium