VITAMIN K1 IN HUMAN MILK

Abstract

Fatal vitamin K deficiency haemorrhage has been observed in breast fed babies. Though the incidence of vitamin K deficiency haemorrhage seems to be low in exclusively breastfed babies in Germany, subclinical vitamin K deficiency is by far more common as demonstrated in recent studies. Vitamin K concentrations in human milk are lower than in cow's milk and infant formula, however, nothing is known about the factors determinating the vitamin K1 concentrations in human milk. Vitamin K1 concentrations in human milk were studied during the first five weeks of lactation with respect to a) stage of lactation, b) interindividual differences, c) relationship of vitamin K1 to other lipids, and d) influence of oral supplements of vitamin K1 given to the mother. Milk samples from 9 mothers were collected on day 1,3,5,22,29 and 36 of lactation using standarized techniques.a) Vitamin K1 concentrations in colostral milk, day 1-5 (median 1,8 ng/ml) were significanctly higher than in mature milk, day 22-36 (median 1,1 ng/ml) (Wilcoxon U-Test p< 0,01). These changes during the course of lactation must be considered for estimation of the vitamin K supply in breastfed babies.b) Vitamin K concentrations both for colostral and mature milk were found to vary widely: colostral milk 0,6-4,4 ng/ml, mature milk 0,4 - 2,8 ng/ml.c) For colostral milk regression analyses revealed good correlations of vitamin K1 to cholesterol but none to total lipid and phospholipids, whereas no correlation to either lipid was observed for mature milk. Cholesterol appears to have a role in vitamin K1 secretion into colostral milk.d) Vitamin K1 concentrations of maternal milk were influenced by oral supplements given to the mother. Even with a dose of 100 μ vitamin K1 (similar to the dose which may be ingested with a meal) a twofold increase of the vitamin K1. content of breast milk was observed. These data suggest that mutritional factors may influence the vitamin concentration in human milk. Vitamin K supplements for breastfeeding mothers on vitamin K1 poor diets could improve the vitamin K supply of these babies.