Vitamin K insufficiency predicts incidence of frailty in community-dwelling older adults: The Otassha Study

Introduction: Vitamin K is a fat-soluble vitamin discovered as an essential factor for blood coagulation. It is suggested that vitamin K can benefit several aging-related diseases, including osteoporosis, osteoarthritis, and dementia. We previously reported the cross-sectional association of vitamin K insufficiency with frailty in community-dwelling older adults.

Materials and methods: In October 2020, a health examination of community-dwelling older adults (The Otassha Study) was performed, including frailty evaluation and blood tests. We used a ucOC and OC ratio (ucOC/OC) to indicate vitamin K insufficiency. One year later, we conducted a follow-up evaluation of frailty on 518 people who were not frail at baseline. The serum ucOC/OC at the baseline examination was divided into quartiles (Q1, Q2, Q3, and Q4). Odds ratio (OR) and 95% confidence interval (CI) were calculated using multivariate binary logistic regression for each quartile of ucOC/OC to determine the risk of incident frailty in the follow-up study, with the lowest quartile (Q1) as the reference.

Results: Among the 518 older adults who were not frail at baseline, 66 people (12.7%) became frail in the follow-up study. In the multivariate binary logistic regression analysis, setting the lowest quartile of ucOC/OC (Q1) as a reference, the OR of the incident frailty in the highest quartile (Q4) was 2.53 (95% CI 1.07, 4.92) which was significantly different from Q1.

Conclusion: The findings of this longitudinal study suggest that vitamin K insufficiency has nutritional importance in predicting the future incidence of frailty in the Japanese older adult population.