Low serum calcium and high parathyroid hormone levels in neonates fed 'humanized' cow's milk-based formula

Am J Dis Child. 1991 Aug;145(8):941-5. doi: 10.1001/archpedi.1991.02160080119033.


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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Analysis of Variance
  • Calcium / blood*
  • Humans
  • Hypocalcemia / etiology
  • Infant Food / adverse effects*
  • Infant, Newborn
  • Milk, Human
  • Parathyroid Hormone / blood*
  • Phosphates / blood
  • Phosphorus


  • Parathyroid Hormone
  • Phosphates
  • Phosphorus
  • Calcium