The Differential Effects of Vitamin K Across Glycaemic Outcomes in Prediabetes and Type 2 Diabetes Mellitus.

Vitamin K supplementation significantly reduced fasting blood glucose (FBG) compared to control.

• SMD = -0.22, 95% CI (-0.39 to -0.05)
• Analysis based on eight RCTs
• Mean age in vitamin K group was 50.58 ± 6.91 years; control group 48.19 ± 5.41 years
• Results reported as standardised mean difference (SMD) with 95% confidence intervals

Vitamin K supplementation significantly reduced HbA1c compared to control.

• MD = -1.00%, 95% CI (-1.92 to -0.07)
• Low doses of vitamin K2 were specifically associated with reduced HbA1c
• Analysis derived from eight relevant RCTs identified from PubMed, Scopus, and manual screening

Vitamin K supplementation significantly reduced insulin resistance as measured by HOMA-IR.

• MD = -0.63, 95% CI (-1.20 to -0.06)
• Low doses of vitamin K1 were associated with reduced HOMA-IR
• An intervention duration of less than 12 weeks was associated with reduced HOMA-IR
• Analysis based on eight RCTs

Vitamin K supplementation had no significant effect on fasting insulin levels.

• SMD = -0.39, 95% CI (-0.91 to 0.13), p = 0.15
• Result was non-significant
• Analysis based on eight RCTs

Vitamin K supplementation had no significant effect on beta cell function as measured by HOMA-β.

• MD = 6.56, 95% CI (-3.89 to 17.01), p = 0.2184
• Result was non-significant
• Analysis based on eight RCTs

Only eight RCTs were found relevant for the meta-analysis, and the authors noted limited number of trials with moderate quality.

• Studies were identified from PubMed, Scopus, and manual screening
• Only RCTs were considered for inclusion
• The Meta online tool was used to analyse data
• Authors concluded that 'the limited number of trials with moderate quality warrants larger, longer-term RCTs with rigorous methodology'

Different isoforms of vitamin K were differentially associated with specific glycaemic outcomes.

• Low doses of vitamin K2 were associated with reduced HbA1c
• Low doses of vitamin K1 were associated with reduced HOMA-IR
• Authors called for 'direct comparisons of vitamin K isoforms to better assess therapeutic potential'