Vitamin K status in healthy volunteers.

Abstract

Vitamin K's recommended dietary allowance (RDA) is based on the hepatic requirement for clotting factor synthesis, but substantial concentrations of undercarboxylated extra-hepatic Gla-proteins are found in the circulation of non-supplemented individuals. This suggests that vitamin K intake above the RDA is required for an optimal extra-hepatic vitamin K status. Circulating uncarboxylated osteocalcin (ucOC) and desphospho-uncarboxylated matrix Gla-protein (dp-ucMGP) are considered markers of the vitamin K status in bone and the vasculature, respectively. We measured these markers in 896 samples of healthy volunteers and defined target groups for vitamin K supplementation based on increased levels indicative of tissue-specific vitamin K deficiency. We studied the response to vitamin K supplements at different states of vitamin K deficiency by measuring the circulating dp-ucMGP level in samples from two short-term trials on menaquinone-7 (MK-7, vitamin K2) supplementation in 42 children and 68 adults. Children had high ucOC levels (3.4-96.9 ng ml(-1)); other age groups had values in the range of 1.5-5.0 ng ml(-1). From the age of 40 years, dp-ucMGP levels gradually increased. Children and adults with more pronounced vitamin K deficiency gave the highest responses to MK-7 supplementation. Children and adults above 40 years showed the largest tissue-specific vitamin deficiency and accordingly may benefit from MK-7 supplementation to improve their extra-hepatic vitamin K status.

• Authors: E Theuwissen, E J Magdeleyns, L A J L M Braam, K J Teunissen, M H Knapen, I A G Binnekamp, M J H van Summeren, C Vermeer
• Journal: Food & function (Food Funct) Vol. 5 Issue 2 Pg. 229-34 (Feb 2014) ISSN: 2042-650X [Electronic] England
• PMID: 24296867 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• Calcium-Binding Proteins
• Extracellular Matrix Proteins
• matrix Gla protein
• Osteocalcin
• Vitamin K

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Biomarkers (blood)
• Calcium-Binding Proteins (blood)
• Child
• Child, Preschool
• Dietary Supplements (analysis)
• Extracellular Matrix Proteins (blood)
• Female
• Healthy Volunteers
• Humans
• Male
• Middle Aged
• Osteocalcin (blood)
• Vitamin K (administration & dosage, blood)
• Vitamin K Deficiency (blood, drug therapy)
• Young Adult