title: Vitamin K in colostrum and mature human milk over the lactation period--a cross-sectional study.
abstract: Vitamin K was quantitated in the milk of four groups of 15 mothers from 1 d to 6 mo postpartum in a cross-sectional study. Concentrations were 7.52 +/- 5.90 and 6.36 +/- 5.32 nmol/L (3.39 +/- 2.66 and 2.87 +/- 2.40 micrograms/L) in colostrum and mature milk, respectively. Differences between colostrum and mature milk or among samples of mature milk collected at 1, 3, and 6 mo were not statistically significant. Because of significantly increased volumes of milk over the lactation period, approximately twice as much vitamin K was delivered in mature milk as in colostrum. Within normal ranges, concentrations of vitamin K in milk were not predicted by dietary intake of vegetables or fat. Vitamin K was correlated with fat in colostrum and was localized in the lipid core of the milk fat globule but was not associated with membranes. Vitamin K in human milk is insufficient to meet recommended intakes for infants aged less than 6 mo. Population and clinical studies are needed to assess the vitamin K status of exclusively breast-fed infants and to evaluate current recommendations.
authors.affiliation: Department of Biochemistry, University of Arizona, Tucson 85721.
authors.forename: L M
authors.initials: LM
authors.lastname: Canfield
authors.forename: J M
authors.initials: JM
authors.lastname: Hopkinson
authors.forename: A F
authors.initials: AF
authors.lastname: Lima
authors.forename: B
authors.initials: B
authors.lastname: Silva
authors.forename: C
authors.initials: C
authors.lastname: Garza
mesh_terms: D000328:Adult; D003126:Colostrum / Q000737:chemistry*; D003430:Cross-Sectional Studies; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007774:Lactation / Q000378:metabolism*; D008055:Lipids / Q000032:analysis; D008895:Milk, Human / Q000737:chemistry*; D011247:Pregnancy; D014675:Vegetables; D014812:Vitamin K / Q000032:analysis*
chemical_list: D004041:Dietary Fats; D008055:Lipids; D014812:Vitamin K