The Effect of Soy-based Formula on Infants' Bone Mineral Density

Sim, Ji Yun; Han, Heon Seok

Abstract

PURPOSE:We compared the blood chemistry concerning calcium metabolism and bone mineral density (BMD) among the infants fed on soy-based formula (SF), breast milk feeding (BF) and casein-based formula (CF).
METHODS
Fifty one term neonates delivered at Chungbuk National University Hospital from June 2001 to August 2003, were recruited. They were divided into three feeding groups (BF=20, SF=19, CF=12) by parent's own volition. Breast feeding and artificial formulae were given till three months of age, thereafter weaning food was added freely. Blood chemistry including calcium, phosphorus, and alkaline phosphatase were measured at 5, 12, and 36 months of age. BMD was measured at birth, 5, 12, and 36 months of age.
RESULTS
Serum calcium and alkaline phosphatase were not different among the three feeding groups until 36 months of age. At 5 months of age, serum phosphorus (P<0.05) and BMD (P<0.001) were significantly lower in SF group, but thereafter no difference was found in theses parameter until 36 months of age. After birth lumbar spine BMD decreased to the lowest level at 5 months and increased to the birth level at 36 months of age.
CONCLUSION
In spite of high mineral intake in SF group, the lowest serum phosphorus and lumbar BMD at 5 months of age suggest poor intestinal mineral absorption. Methods need to be developed to increase intestinal mineral absorption.