Vitamin K1 and K2 in Infant Human Liver

SUMMARY It is not known to what extent humans store vitamin K in liver. We measured hepatic concentrations of vitamin K1 (phylloquinone) and K2 (menaquinones) in 11 human livers (eight infants and three adults). Relatively small amounts of vitamin K were found in the liver at any age compared to other fat soluble vitamins. Vitamin K1 was the predominant form with much smaller concentrations of vitamin K2. Long‐chain menaquinones (vitamin K2) were readily identified in most liver specimens. Hepatic vitamin K2 concentrations also increased with increasing age. These observations have implications for vitamin K supplementation in infants.