Improving the vitamin K status of breastfeeding infants with maternal vitamin K supplements.

OBJECTIVE: To increase the phylloquinone (vitamin K1) concentration of human milk with maternal oral phylloquinone supplements such that both the phylloquinone intake of breastfed infants and their serum concentrations of phylloquinone would approach those of formula-fed infants who are known to be at much less risk for hemorrhagic disease of the newborn.

DESIGN: Two stages: stage I, longitudinal, randomized study of 6 weeks' duration; and stage II, longitudinal, randomized, double-blind, placebo-controlled study of 12 weeks' duration.

SETTING: Patients from a private pediatric practice in Madison, WI.

PATIENTS: Stage I: sequential sampling of 20 lactating mothers to determine the level of maternal supplementation needed in stage II. Ten mothers received 2.5 mg/d oral phylloquinone, and 10 mothers received 5.0 mg/d oral phylloquinone. Stage II: sequential sampling of 22 human milk-fed infants and lactating mothers. All infants received 1 mg of phylloquinone at birth. Eleven mothers received a placebo; 11 mothers received 5 mg/d phylloquinone.

MEASUREMENTS AND RESULTS: In stage I, both 2.5 and 5.0 mg/d phylloquinone significantly increased the phylloquinone content of human milk at both 2 and 6 weeks. As expected, 5.0 mg had a greater effect (mean +/- SD, 58.96 +/- 25.39 vs 27.12 +/- 12.18 ng/mL at 2 weeks). In stage II, the vitamin K-supplemented group had significantly higher maternal serum phylloquinone concentrations, higher phylloquinone milk concentrations, and higher infant plasma phylloquinone concentrations at 2, 6, and 12 weeks compared with the placebo group. At 12 weeks infant phylloquinone intakes were significantly higher for the vitamin K group than the placebo group (9.37 +/- 4.55 vs 0.15 +/- 0.07 microgram/kg per day). This corresponded to a plasma phylloquinone concentration in the vitamin K group of 2.84 +/- 3.09 vs 0.34 +/- 0.57 ng/mL in the placebo group. At 12 weeks, the prothrombin times did not differ between the groups, but the des-gamma-carboxy-prothrombin (partially carboxylated prothrombin thought to be a measure of vitamin K deficiency) was significantly elevated in the placebo group compared with the vitamin K group (1.48 +/- 1.19 vs 0.42 +/- 0.55 ng/mL).

CONCLUSION: In exclusively breastfed infants who receive intramuscular phylloquinone at birth, the vitamin K status as measured by plasma phylloquinone and des-gamma-carboxy-prothrombin concentrations is improved by maternal oral supplements of 5 mg/d phylloquinone through the first 12 weeks of life.