Vitamin K and osteoarthritis: is there a link?

An atlas of causal association between micronutrients and osteoarthritis

OBJECTIVE

This study examines the causal relationships between serum micronutrients and site-specific osteoarthritis (OA) using Mendelian Randomization (MR).

METHODS

This study performed a two-sample MR analysis to explore causal links between 21 micronutrients and 11 OA outcomes. These outcomes encompass overall OA, seven site-specific manifestations, and three joint replacement subtypes. Sensitivity analyses using MR methods, such as the weighted median, MR-Egger, and MR-PRESSO, assessed potential horizontal pleiotropy and heterogeneity. Genome-wide association summary statistical data were utilized for both exposure and outcome data, including up to 826,690 participants with 177,517 OA cases. All data was sourced from Genome-wide association studies datasets from 2009 to 2023.

RESULTS

In the analysis of associations between 21 micronutrients and 11 OA outcomes, 15 showed Bonferroni-corrected significance (P < 0.000216), without significant heterogeneity or horizontal pleiotropy. Key findings include strong links between gamma-tocopherol and spine OA (OR = 1.70), and folate with hand OA in finger joints (OR = 1.15). For joint replacements, calcium showed a notable association with a reduced likelihood of total knee replacement (TKR) (OR = 0.52) and total joint replacement (TJR) (OR = 0.56). Serum iron was significantly associated with an increased risk of total hip replacement (THR) (OR = 1.23), while folate indicated a protective effect (OR = 0.95). Various sex-specific associations were also uncovered.

CONCLUSION

These findings underscore the critical role of micronutrients in osteoarthritis, providing valuable insights for preventive care and potential enhancement of treatment outcomes.

Vitamin K2 in Health and Disease: A Clinical Perspective

Vitamins are essential organic compounds that vary widely in chemical structure and are vital in small quantities for numerous biochemical and biological functions. They are critical for metabolism, growth, development and maintaining overall health. Vitamins are categorised into two groups: hydrophilic and lipophilic. Vitamin K (VK), a lipophilic vitamin, occurs naturally in two primary forms: phylloquinone (VK1), found in green leafy vegetables and algae, and Menaquinones (VK2), present in certain fermented and animal foods and widely formulated in VK supplements. This review explores the possible factors contributing to VK deficiency, including dietary influences, and discusses the pharmacological and therapeutic potential of supplementary VK2, examining recent global clinical studies on its role in treating diseases such as osteoporosis, osteoarthritis, rheumatoid arthritis, cardiovascular disease, chronic kidney disease, diabetes, neurodegenerative disorders and cancers. The analysis includes a review of published articles from multiple databases, including Scopus, PubMed, Google Scholar, ISI Web of Science and CNKI, focusing on human studies. The findings indicate that VK2 is a versatile vitamin essential for human health and that a broadly positive correlation exists between VK2 supplementation and improved health outcomes. However, clinical data are somewhat inconsistent, highlighting the need for further detailed research into VK2's metabolic processes, biomarker validation, dose-response relationships, bioavailability and safety. Establishing a Recommended Daily Intake for VK2 could significantly enhance global health.

The Rotterdam Study. Design update and major findings between 2020 and 2024

The Rotterdam Study is a population-based cohort study, started in 1990 in the district of Ommoord in the city of Rotterdam, the Netherlands, with the aim to describe the prevalence and incidence, unravel the etiology, and identify targets for prediction, prevention or intervention of multifactorial diseases in mid-life and elderly. The study currently includes 17,931 participants (overall response rate 65%), aged 40 years and over, who are examined in-person every 3 to 5 years in a dedicated research facility, and who are followed-up continuously through automated linkage with health care providers, both regionally and nationally. Research within the Rotterdam Study is carried out along two axes. First, research lines are oriented around diseases and clinical conditions, which are reflective of medical specializations. Second, cross-cutting research lines transverse these clinical demarcations allowing for inter- and multidisciplinary research. These research lines generally reflect subdomains within epidemiology. This paper describes recent methodological updates and main findings from each of these research lines. Also, future perspective for coming years highlighted.

Genetically predicted vitamin K levels and risk of osteoarthritis: Mendelian randomization study

OBJECTIVE

Osteoarthritis (OA) is a progressive disease for which there is no disease modifying therapy. Vitamin K levels and vitamin K antagonism have been associated with risk and progression of OA which may have direct implications for clinical management, but these observational findings are susceptible to confounding. We aimed to estimate the causal association between vitamin K and OA risk using Mendelian randomisation (MR).

METHODS

We used data from the largest genome-wide association study (GWAS) of OA to date (up to 826,690 individuals) to estimate the effect of genetically predicted vitamin K level (instrumented using four variants derived from a GWAS of 2,138 individuals) on risk of all OA types, knee, hip, spine, hand OA, and total joint replacement. We employed the inverse-variance weighted method for the primary analysis and, in a series of sensitivity analyses, adjusted for sub-genome wide significant instruments and tested for potential bias from pleiotropy.

RESULTS

We showed that genetically predicted vitamin K levels were not causally associated with risk of OA overall (OR 0.98 per unit increase in log-transformed vitamin K1; 95%CI 0.96-1.01), knee (OR 0.98; 0.92-1.03), hip (OR 0.97; 0.88-1.07), spine (OR 0.97; 0.90-1.04), hand OA (OR 0.97; 0.91-1.04) or joint replacement (OR 0.96; 0.89-1.04). Results were similar across all sensitivity analyses.

CONCLUSION

We found little evidence of a causal association between genetically predicted vitamin K and OA risk. Larger genetic and interventional studies of vitamin K are required to confirm our findings.