Vitamin K status in human tissues: tissue-specific accumulation of phylloquinone and menaquinone-4

TLDR

The study aimed to determine whether vitamin K distribution varies across human tissues. The authors quantified vitamin K (K1 and MK‑4) levels in postmortem human tissues (brain, heart, kidney, liver, lung, pancreas) to assess tissue‑specific distribution. Vitamin K1 was abundant in liver, heart, and pancreas but scarce in brain, kidney, and lung, whereas MK‑4 was higher than K1 in brain and kidney and low in liver, heart, and lung, indicating tissue‑specific distribution patterns similar to rats and suggesting a previously unrecognized physiological role for vitamin K in heart, brain, and pancreas.

Abstract

We measured the vitamin K status in postmortem human tissues (brain, heart, kidney, liver, lung, pancreas) to see if there is a tissue-specific distribution pattern. Phylloquinone (K1) was recovered in all tissues with relatively high levels in liver, heart and pancreas (medians, 10.6 (4.8), 9.3 (4.2), 28.4 (12.8) pmol(ng)/g wet weight tissue); low levels (< 2 pmol/g) were found in brain, kidney and lung. Menaquinone-4 (MK-4) was recovered from most of the tissues; its levels exceeded the K1 levels in brain and kidney (median, 2.8 ng/g) and equalled K1 in pancreas. Liver, heart and lung were low in MK-4. The higher menaquinones, MK-6-11, were recovered in the liver samples (n 6), traces of MK-6-9 were found in some of the heart and pancreas samples. The results show that in man there are tissue-specific, vitamin-K distribution patterns comparable to those in the rat. Furthermore, the accumulation of vitamin K in heart, brain and pancreas suggests a hitherto unrecognized physiological function of this vitamin.