The unexpected role of B vitamins in osteoarthritis: a call for caution

<i>Background</i>: The purpose of this study was to investigate the single and mixed effects of B vitamins on OA. <i>Methods</i>: Data from the National Health and Nutrition Examination Survey (NHANES) database, from 2003 to 2018, were extracted. A weighted multiple logistic regression model was used to assess the association between B vitamin intake alone and OA. In addition, Bayesian kernel machine regression (BKMR), weighted quantile sum (WQS) regression and quantile g-calculation (qgcomp) models were used to evaluate the combined effects of six B vitamins on OA. Additionally, restricted cubic spline (RCS) was used to assess possible nonlinear associations between individual B vitamins and OA. <i>Results</i>: The study found that vitamin B₁ (OR = 1.17, 95%CI = 1.05-1.30), vitamin B₂ (OR = 1.12, 95%CI = 1.02-1.22), vitamin B₁₂ (OR = 1.01, 95%CI = 1.00-1.01) and total folate (OR = 1.001, 95%CI = 1.000-1.001) increased the risk of OA. Subgroup analysis showed that the association was more significant in people older than 65 and in women. In addition, the mixed effect model also suggested that the mixed effect of six B vitamin mixtures on OA risk was greater. Among them, vitamin B₂ and vitamin B₁₂ contributed the most to the promotion of OA disease by B-complex vitamins. Folic acid, however, showed a protective effect on the bone and joints in the mixed effect model. <i>Conclusion</i>: The data show that the intake of B vitamins accelerates the occurrence and progression of OA. People with OA disease and those at high risk should be cautious about using vitamin B as a dietary supplement.