Plasma and red cell folacin in cow's milk-fed infants and children during the first 2 years of life: the significance of boiling pasteurized cow's milk.

Plasma and red blood cell folacin concentrations (Lactobacillus casei activity) and other pertinent parameters have been studied in 10 infants and children fed home-made cow's milk mixtures until 5 months of age. The folacin concentrations have been estimated in 44 samples of pasteurized cow's milk before and after pretreatment with conjugase. The effect of boiling on the folacin concentration has been studied in 11 samples of pasteurized cow's milk. During the time the infants were fed home-made cow's milk mixtures they developed signs of folacin deficiency, as judged from the plasma and red cell folacin concentrations as well as from other hematologic studies. The mean folacin concentration in pasteurized cow's milk was 168.9 SEM 7.80, and range 72 to 262 nmol/liter. Pretreatment with conjugase did not increase the folacin concentrations. During boiling for 1 min 2/3 of the folacin activity was lost. This could be prevented by adding ascorbic acid, 1 mg/ml, before the boiling procedure. The folacin deficiency observed in the infants is probably secondary to loss of folacin activity in connection with the preparation of the cow's milk mixtures.