Vitamin K – an update, part 1

Peer-reviewed | Manuscript received: February 17, 2017 | Revision accepted: August 08, 2017

Part 1: Basic nutritional facts

Introduction

Although neonatal prophylaxis for the prevention of vitamin K deficiency- related blood clotting disorders is standard in many countries [1], vitamin K intake is otherwise rarely discussed. This can be attributed to the inconsistent evidence regarding the other functions of vitamin K.

Here we discuss the issues surrounding the fact that vitamin K is also involved in the inhibition of calcification of soft tissues (especially blood vessels) as well as in the mineralization of bones, and that due to the activation of extrahepatic vitamin K-dependent (VKD) proteins such as matrix gla protein (matrix gamma-carboxyglutamic acid protein = MGP) and osteocalcin (OC), there seems to be an association between vitamin K status and the risk of developing atherosclerosis and osteoporosis.

Abstract

In the first part of this two-part update on the basic nutritional facts on vitamin K, following an extensive literature search, we discuss the occurrence of this essential micronutrient in food, and its consumption, metabolism, functions and biomarkers. We will focus in particular on the functions that go beyond the vitamin’s contribution to blood clotting, on the calcium paradox, and on vitamin K antagonists. According to our findings, it is not necessary to change eating habits with regard to foodstuffs that contain vitamin K when starting anticoagulants.

Keywords: Vitamin K, menaquinone, phylloquinone, vitamin K cycle, matrix gla protein, osteocalcin, vitamin K antagonists

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References

Tables 3 + 4