Human Milk Studies

Abstract

Individual and mixed samples of breast milk from women with approximately the same milk flow and on apparently satisfactory dietaries were tested biologically by means of several different controlled methods for their vitamin B and vitamin G potency before and during the supplementary additions of 10 gm. of yeast daily to the accustomed maternal dietary. In both the vitamin B and vitamin G studies there was a progressive increase in the growth of the test animals simultaneously with increased consumption of breast milk. This was true whether the milk was secreted during the preyeast period or the yeast period. The concentration of vitamin G in breast milk was increased from 0.2 unit per cubic centimeter during the preyeast period to 0.3 unit during the yeast period; an increase of approximately 0.1 unit per cubic centimeter, by the addition of 10 gm. of yeast to the maternal diet for the milk tested. As judged by the rat growth rate method, no increase in the antineuritic potency of breast milk occurred under yeast therapy. The concentration of approximately 0.1 unit of vitamin B per cubic centimeter of breast milk remained unchanged. By a series of observations in which the caloric food consumption of the experimental animals was controlled, further evidence was given that the vitamin G concentration is increased, but that no change occurs in the vitamin B content of breast milk with this enrichment of the maternal diet. Nitrogen metabolic balances on test rats receiving vitamins B and G from breast milk, before and after the addition of yeast to the maternal diet, showed a greater retention of nitrogen during the latter period in all animals. The composition of the growth of the animals with vitamin G from breast milk was higher in nitrogen content than the growth of the animals with vitamin B supplied by equal quantities of milk. From the observations on the women of this investigation, it can be concluded that the biological potency of breast milk can be enhanced by the addition of a concentrated source of the vitamin B complex to the average dietary. At the same time, the mothers themselves experienced less fatigue and a more satisfactory feeling of well being. These studies further suggest the need for more adequate knowledge of diet for lactating women in order that an approach can be made toward a nearly optimal food provision for both the mother and her dependent infant.