The use of vitamin K supplementation to achieve INR stability: a systematic review and meta-analysis

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#anticoagulants #dietary-supplements #humans #international-normalized-ratio #vitamin-k

The use of vitamin K supplementation to achieve INR stability: a systematic review and meta-analysis

Kramps et al., 2013 | J Am Assoc Nurse Pract | Meta Analysis

Citation

Kramps Melissa, Flanagan Abigail, Smaldone Arlene. The use of vitamin K supplementation to achieve INR stability: a systematic review and meta-analysis. J Am Assoc Nurse Pract. 2013-Oct;25(10):535-544. doi:10.1111/1745-7599.12022

Abstract

PURPOSE: Systematically review and quantitatively synthesize evidence on use of oral vitamin K supplementation in reducing international normalized ratio (INR) variability. DATA SOURCES: PubMed, The Cochrane Library, PsycINFO, Cumulative Index of Nursing and Allied Health Literature (CINAHL), Turning Research Into Practice (TRIP), Web of Science were searched for studies meeting predetermined inclusion/exclusion criteria. Five studies meeting criteria (three randomized trials, one quasi-experimental pre-post study, one retrospective case series) were appraised for quality and data synthesized by two reviewers. Pooled effect size of time in INR therapeutic range (TTR) was estimated using random effects meta-analysis. CONCLUSIONS: Pooled effect size representing data from four studies (678 subjects) was 0.31, 95% confidence interval 0.03-0.59 (Cochran Q = 7.1; p = .07; I(2) = 57.8) and favored vitamin K supplementation. Given wide variability among individual studies, there is not enough evidence to advise for or against the routine use of vitamin K supplementation to achieve INR stability. However, evidence does suggest that it may be of some benefit for some patients with INR instability. IMPLICATIONS FOR PRACTICE: There is insufficient evidence to support routine supplementation with vitamin K in patients on chronic anticoagulation therapy but select patients, particularly those with persistent INR instability despite known adherence to regimen and no dietary or drug-drug interactions, may benefit from the intervention. Future research is warranted.

Key Findings

Pooled effect size representing data from four studies (678 subjects) was 0.31, 95% confidence interval 0.03-0.59 (Cochran Q = 7.1; p = .07; I(2) = 57.8) and favored vitamin K supplementation. Given wide variability among individual studies, there is not enough evidence to advise for or against the routine use of vitamin K supplementation to achieve INR stability. However, evidence does suggest that it may be of some benefit for some patients with INR instability. IMPLICATIONS FOR PRACTICE: Ther

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population inr instability
Sample Size 678
Age Range See abstract
Condition See abstract

MeSH Terms

  • Anticoagulants
  • Dietary Supplements
  • Humans
  • International Normalized Ratio
  • Vitamin K
  • Vitamins

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Journal Article, Meta-Analysis, Systematic Review
  • Vertical: vitamin-k

Provenance

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