Dietary Requirements for Fertility and Lactation. XXV. Does Amount of Fat in Diet Influence Vitamin B Requirements for Lactation? ∗

Abstract

The experimental data presented by Evans and Lepkovsky 1 in support of the thesis that fat produces a sparing action on vitamin B suggested an attempt to determine whether increasing amounts of fat in the ration would influence the incidence of infant mortality on a maternal diet deficient only in vitamin B or the vitamin B complex. The lactation efficiency index was studied on rations containing 3 levels of fat intake, namely 10, 20, and 30. The fat used was lard. Two types of yeast were used as a source of vitamin B complex for the control diets, i. e. Northwestern dehydrated, and Fleischman's dried.† The same types of yeast, autoclaved, were used as a source of vitamin G for the pathological animals. Of the former 10% was used in the ration and of the latter, 15%. A total of 72 mothers with litters were employed. It was realized that, because of the large amounts of vitamin B required for lactation compared with that for growth, nothing like normal rearing of young could be anticipated by virtue of such a modification in the diet as the introduction of additional amounts of fat, since the basal rations were deficient in either the B vitamin or B vitamins. Yet, if large amounts of fat produce a sparing action on vitamin B requirements, the young should have been reared for a longer term before collapse ensued. The results, however, indicate no benefits derived in lactation from the additional increments of fat available to the nursing mother.

A critical examination of the data of Evans and Lepkovsky does not, in our opinion, justify the interpretation that fats have any sparing action on vitamin B requirements.