Vitamin K supplementation and bone mineral density in dialysis: results of the double-blind, randomized, placebo-controlled RenaKvit trial

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#humans #bone-density #vitamin-k #renal-dialysis #absorptiometry-photon

Vitamin K supplementation and bone mineral density in dialysis: results of the double-blind, randomized, placebo-controlled RenaKvit trial

Levy-Schousboe et al., 2023 | Nephrol Dial Transplant | Rct

Citation

Levy-Schousboe Karin, Marckmann Peter, ... Hansen Ditte. Vitamin K supplementation and bone mineral density in dialysis: results of the double-blind, randomized, placebo-controlled RenaKvit trial. Nephrol Dial Transplant. 2023-Sep-29;38(10):2131-2142. doi:10.1093/ndt/gfac315

Abstract

BACKGROUND: Vitamin K deficiency is highly prevalent in patients on dialysis and may contribute to their low bone mineral density (BMD) and increased risk of fracture. This study investigated the effect of menaquinone-7 (MK-7) supplementation on BMD in patients on chronic dialysis. METHODS: In a multicentre, double-blind, placebo-controlled intervention trial, 123 patients on chronic dialysis were randomised to a daily oral supplement of either MK-7 360 µg or placebo for 2 years. BMD of the distal radius (1/3, mid, ultradistal and total), femoral neck, lumbar spine (L1-L4) and whole body was assessed by dual-energy X-ray absorptiometry. Serum levels of vitamin K1 and MK-7 and plasma levels of total osteocalcin, dephosphorylated-uncarboxylated matrix Gla protein and protein induced by vitamin K absence II were measured to assess vitamin K status. RESULTS: After 2 years, an accelerated BMD loss of the 1/3 distal radius was found with MK-7 supplementation {mean difference of changes relative to placebo -0.023 g/cm2 [95% confidence interval (CI) -0.039 to -0.008]}, whereas the decrease in lumbar spine BMD seen in the placebo group was prevented [mean difference of changes between groups 0.050 g/cm2 (95% CI 0.015-0.085)]. No significant effects were observed at the remaining skeletal sites. Vitamin K status strongly improved in MK-7-supplemented participants. CONCLUSION: Compared with placebo, an accelerated BMD loss of the 1/3 distal radius was found after 2 years of MK-7 supplementation, whereas a decline in lumbar spine BMD was prevented. As such, MK-7 supplementation might modify BMD site-specifically in patients on dialysis. In aggregate, our findings do not support MK-7 supplementation to preserve bone in patients on dialysis.

Key Findings

After 2 years, an accelerated BMD loss of the 1/3 distal radius was found with MK-7 supplementation {mean difference of changes relative to placebo -0.023 g/cm2 [95% confidence interval (CI) -0.039 to -0.008]}, whereas the decrease in lumbar spine BMD seen in the placebo group was prevented [mean difference of changes between groups 0.050 g/cm2 (95% CI 0.015-0.085)]. No significant effects were observed at the remaining skeletal sites. Vitamin K status strongly improved in MK-7-supplemented part

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 123
Age Range See abstract
Condition deficiency

MeSH Terms

  • Humans
  • Bone Density
  • Vitamin K
  • Renal Dialysis
  • Absorptiometry, Photon
  • Vitamin K 2
  • Dietary Supplements
  • Double-Blind Method

Evidence Classification

  • Level: Rct
  • Publication Types: Randomized Controlled Trial, Multicenter Study, Journal Article, Research Support, Non-U.S. Gov't
  • Vertical: vitamin-k-bone

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09