VITAMIN-K1 (PHYLLOQUINONE) AND VITAMIN-K2 (MENAQUINONE) STATUS IN NEWBORNS DURING THE 1ST WEEK OF LIFE

  • 1 January 1988
    • journal article
    • research article
    • Vol. 81  (1) , 137-140
Abstract
Since 1961 the Committee on Nutrition of the American Academy of Pediatrics has recommended that prophylactic vitamin K be administered parenterally to all newborn infants, although the exact requirement for vitamin K in the newborn infant is unknown. There is little information about the vitamin K1 (phylloquinone, present in green vegetables) and vitamin K2 (menaquinones, synthesized by intestinal flora) status of newborn infants. In this study during the first week of life vitamin K status was assessed by measuring serum concentrations of phylloquinone in 23 mother-infant pairs at the time of birth. Maternal phylloquinone concentration (1.7 .+-. 1.0 ng/mL, mean .+-. SD) was significantly higher (P < .02) than cord serum concentrations (1.1 .+-. 0.6 ng/mL). All infants were then given a standard 1-mg injection of vitamin K1. Ten infants were fed formula (containing 58 ng/mL of vitamin K1) and 13 were exclusively breast-fed. On day 5 of life, serum concentrations of vitamin K1 did not differ between breast-fed (21.0 .+-. 12.4 ng/ml) and formulae-fed (27.5 .+-. 9.7 ng/ml) infants, reflecting the large amounts of parenteral vitamin K1 at birth. During the first week of life, formula-fed infants had much higher fecal concentrations of vitamin K1 (due to large oral intake) and more significant quantitites (.gtoreq. 200 pmol/g of dry weight) of fecal menaquinones (reflecting differences in bacterial flora) than did breast-fed infants. Although there is uncertainty regarding the extent of vitamin K2 utilization in infants as well as the relative bipotency of the two forms of the vitamin, these data may have important implications for the worldwide problem of hemorrhagic disease of the newborn.