115 EFFECT OF DIFFERENT MILK DIETS ON GASTROINTESTINAL BLOOD LOSS IN INFANCY

Abstract

Gastrointestinal (GI) blood loss is an important determinant of iron status during the first year of life, and the most difficult to measure accurately. Fresh cow milk has been thought to increase GI blood loss. Thirty seven infants 2-9 mo of age admitted to a Nutrition Rehabilitation Research Center who were healthy and growing well were exclusively given a) powdered whole cow milk, b) maternalized proprietary formula, c) soy base formula and d) fresh pasteurized milk, each during 10 consecutive days. The latter 72 hrs of each cycle, all stool was collected and hemoglobin measured with a new fluorescent assay quantitative and specific for hemoglobin. Stool humidity was an average of 25% with no difference between diets. Fecal concentration of hemoglobin was similar and independent of diet (0,25 mgHb/gr feces) but the volume of stool differed so that absolute blood losses calculated from infants Hb were 0.09, 0.08, 0.04 and 0.03 ml blood/kg/day with fresh cow milk, powdered cow milk, soy based and maternalized cow milk formula respectively (ANOVA p< 0.001, pairwise comparisons all different p<0.05). Blood loss with fresh milk is threefold greater than with modified formula, however, powdered cow milk also induces significantly greater blood loss. GI blood loss is proportional to stool volume, not to Hb concentration in stool. The data indicate that fresh or powdered whole unmodified milk should be avoided during early infancy.