Maternal Supplementation and Vitamin K in Breast Milk

ABSTRACT & COMMENTARY

Synopsis: The low levels of vitamin K that are found in breast milk of mothers of premature infants can be substantially increased by maternal oral supplementation.

Source: Bolisetty S, et al. Vitamin K in preterm breast milk with maternal supplementation. Acta Paediatr 1998;87:960-962.

Exclusively breastfed infants have low vitamin k levels in their plasma at 6-12 weeks of age despite receiving vitamin K prophylaxis at birth. This is due to the much lower concentration of vitamin K in breast milk. It has been estimated that the daily intake of vitamin K by exclusively breastfed babies is less than 0.2 mcg, whereas the vitamin K intake of infants fed with cow’s milk proprietary formulas was 50 mcg/day. Bolisetty and investigators from the Royal Hospital for Women in Sydney, Australia, studied the effect of oral vitamin K supplementation of lactating mothers on the vitamin K levels in their breast milk. Six healthy, lactating mothers who had given birth to preterm infants were given 2.5 mg of oral phylloquinone (vitamin K1) daily. Phylloquinone was measured in the breast milk daily for 14 days. Phylloquinone levels in the breast milk increased from a baseline of 3 ± 2.3 ng/mL to 22.6 ± 16.3 ng/mL after the first dose and then gradually increased to a plateau of 64.2 ± 31.4 ng/mL after the sixth dose. Bolisetty et al conclude that it is possible to increase the vitamin K content of breast milk to levels comparable to that in infant formulas by daily oral supplementation to lactating women.

Comment by Richard A. Ehrenkranz, MD, FAAP

The fourth edition of Guidelines for Perinatal Care continues to recommend that "every neonate should receive a single parenteral 0.5-1.0-mg dose of natural vitamin K1 oxide (phytonadione) within 1 hour of birth" to prevent early and late vitamin K-dependent hemorrhagic disease of the newborn (HDN).1 Infants who have not received this prophylactic dose of vitamin K shortly after birth and who are breastfeeding exclusively are at risk of developing vitamin K-dependent HDN at 4-6 weeks of age due to the low vitamin K content of breast milk. Although the controversy about the potential risk of childhood cancer following IM vitamin K2 has been discounted,3 interest in oral vitamin K prophylaxis and in increasing the vitamin K content of human milk has grown during the past several years. Two recent papers4,5 have demonstrated that a prophylactic dose of a mixed-micellar solution of vitamin K1 containing natural solubilizers with glycocholic acid and lecithin increases serum vitamin K1 levels in normal, breastfed infants. However, multiple doses with this formulation would still be necessary to prevent late HDN. Additionally, it is not currently available in the United States.

In their report, Bolisetty et al have confirmed a previous study6 that the vitamin K1 content of human milk can be increased with maternal oral vitamin K1 supplements. They showed that after two daily doses of 2.5 mg, the human milk vitamin K1 content exceeded the U.S. Recommended Daily Allowance of 26 ng/dL and that the human milk vitamin K1 content plateaued at about 65 ng/mL after six supplemental doses.

Since there is little milk production during the first 24-48 hours after delivery, maternal vitamin K1 supplementation will not protect against early HDN in the newborn. However, the need for repeated IM vitamin K prophylaxis could presumably be replaced someday by oral vitamin K1 prophylaxis to the newborn to protect against early HDN and maternal vitamin K1 supplementation to protect exclusively breastfed infants against late HDN in infants who have not received neonatal IM prophylaxis. Until such an oral vitamin K1 preparation is available in the United States, intramuscular vitamin K1 prophylaxis remains the treatment of choice.

References

1. American Academy of Pediatrics and the American College of Obstetricians and Gynecology. Guidelines for Perinatal Care, 4th ed. 1997:157.

2. Golding J, et al. Childhood cancer, intramuscular vitamin K, and pethidine given during labor. BMJ 1992; 305:341-346.

3. Greer FR. Vitamin K deficiency and hemorrhage in infancy. Clin Perinatal 1995;22:759-777.

4. Schubiger G, et al. Plasma vitamin K1 concentration in and PIVKA-II after oral administration of mixed-micellar or cremophor El-solubilized preparations of vitamin K1 to normal breast-fed newborns. J Pediatr Gastroenterol Nutr 1997;24:280-284.

5. Greer FR, et al. A new mixed micellar preparation for oral vitamin K prophylaxis: Randomized controlled comparison with intramuscular formulation in the breast fed infants. Arch Dis Child 1998;79:300-305.

6. Greer FR, et al. Improving the vitamin K status of breast-feeding infants with maternal vitamin K supplements. Pediatrics 1997;99:88-92.