Evidence Hub

Vitamin K status has no influence on the effect of vitamin D supplementation on bone turnover and cardiovascular markers: a randomized controlled trial

Theiler-Schwetz V, Riedmann U, Zelzer S, Meinitzer A, Schmitt L, Kraus DA, Trummer C, Grübler MR et al.

Frontiers in nutrition, 2026

200 participants

Abstract

Background/objectives: Vitamin K and D co-treatment may have additive effects on bone and cardiovascular health and is frequently used as an over-the-counter supplement. The primary aim of this study was to assess whether the effect of vitamin D supplementation on bone turnover markers and cardiovascular parameters is modified according to vitamin K status at baseline (i.e., serum levels of vitamin K1, MK4 and MK7).

Methods: This is a post-hoc analysis of a randomized controlled vitamin D supplementation (2,800 international units daily for 8 weeks) trial in 200 participants. We measured vitamin K1, MK4 and MK7 by means of the currently available gold standard liquid chromatography tandem mass spectrometric and analysed cardiovascular and bone markers (including 24-h systolic and diastolic blood pressure, glucose and lipid parameters as well as osteocalcin, beta-crosslaps, and procollagen type 1 N-terminal propeptide). The main aim was to analyze whether pre-intervention vitamin K status (moderator) influenced the effects of vitamin D supplementation on outcome measures of bone and cardiovascular health after the intervention (moderation analyses). We also investigated whether vitamin D supplementation effects vitamin K status and whether vitamin K measures correlated with the outcome parameters.

Results: Moderation analyses showed no significant interaction between vitamin K status and the intervention (vitamin D supplementation/placebo) on cardiovascular or bone…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 200 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free