Variations of phylloquinone concentration in human milk at various stages of lactation and in cow's milk at various seasons.

An improved high-performance liquid chromatographic method was used to measure phylloquinone concentrations in human and cow's milk. Concentrations in human milk obtained serially from 10 mothers 3, 8, and 21 days after delivery were found to increase during the course of lactation. No correlation was found between phylloquinone concentration and lipids but a significant negative correlation was observed between phylloquinone and cholesterol concentrations. Determinations in cow's milk showed increased levels during the summer months. Also, levels in cow's milk were significantly higher than in human milk. Notwithstanding marked individual variations in human milk, phylloquinone concentrations in cow's milk always proved higher than in human milk. Results prompt the necessity of protecting breast-fed infants by applying relevant prophylactics measures.