Calcium and fat metabolic balance, and gastrointestinal tolerance in term infants fed milk-based formulas with and without palm olein and palm kernel oils: a randomized blinded crossover study

BACKGROUND Effects of palm olein (POL) on calcium and fat metabolic balance and gastrointestinal (GI) tolerance have been clinically evaluated but its use in combination with palm kernel oil (PKO), and canola oil has not been similarly assessed in infants. METHODS Calcium and fat balance and GI tolerance were evaluated in 33 healthy term infants (age = 68-159 d) in a randomized, double-blinded, 14 d crossover trial at a day care center in Salvador, Brazil; followed by a 4d hospital ward metabolic balance study in 17 of the male subjects. The study compared two commercially available milk-based powdered formulas in Brazil; one containing POL (44% of total fat), PKO (21.7%) and canola oil (18.5%) as predominant fats (PALM), and the other containing none (NoPALM). Occasional human milk (HM) supplementation was allowed at home. RESULTS Formula and HM intakes, and growth were not different (p > 0.05). Calcium absorption (%) for infants fed NoPALM (58.8 ± 16.7%; means ± SD) was higher (p = 0.023) than those fed PALM (42.1 ± 19.2%), but was not significant (p = 0.104) when calcium intake was used as a covariate. Calcium intake was higher (p < 0.001) in NoPALM versus PALM fed infants. However, calcium retention (%) was higher in infants fed NoPALM compared to PALM with (p = 0.024) or without (p = 0.015) calcium intake as a covariate. Fat absorption (%) for NoPALM was greater than PALM fed infants (NoPALM = 96.9 ± 1.2 > PALM = 95.1 ± 1.5; p = 0.020 in Study Period I). Mean rank stool consistency was softer in infants fed NoPALM versus PALM (p < 0.001; metabolic period). Adverse events, spit-up/vomit, fussiness and gassiness were not different (p > 0.05). Formula acceptability was high and comparable for both formula feedings, regardless of HM supplementation. CONCLUSIONS Term infants fed PALM based formula (containing palm olein, palm kernel and canola oils) demonstrated lower calcium retention and fat absorption, and less softer stool consistency versus infants fed NoPALM based formula. Study suggested formula fat differences may affect GI function in infants.