"Association of vitamin D blood deficiency and the rs731236 polymorphism vitamin D receptor with primary knee osteoarthritis in subjects from Mexico".

Vitamin D deficiency is a public health problem worldwide. Some studies have associated serum vitamin D deficiency with knee osteoarthritis. Additionally, some vitamin D receptor polymorphisms have been linked to knee osteoarthritis. This study analyzed the associations among the rs731236 polymorphism of the vitamin D receptor, blood levels of vitamin D and primary knee osteoarthritis in a population from northern Mexico. A case‒control study was conducted from November 2023 to June 2024 with 449 unrelated participants. The vitamin D concentration in the blood was measured semiquantitatively. The presence of vitamin D receptor gene polymorphism genotypes (rs731236) was determined via the rhAmpTM SNP Assay methodology. We used the chi-square test to compare the groups and odds ratios with confidence intervals to calculate risk. In the presence of vitamin D deficiency, subjects showed a 1.5-fold increased risk of primary knee osteoarthritis (59.5%; p = 0.001). Notably, this association remained significant for subjects carrying the AA and AG genotypes and in a dominant model (60.0%, p = 0.023; 61.1%, p = 0.008 and 59.0%, p = 0.042, respectively), after including a multivariate association model. Our study identified a high prevalence of Vitamin D deficiency among individuals with primary knee osteoarthritis. This study suggests a potential association between deficient levels of vitamin D and primary KOA in carriers of the AA and AG rs731236 genotypes. Key Points • We observed a significant 1.5-fold increased risk of primary knee osteoarthritis in the presence of vitamin D deficiency. • Vitamin D deficiency is significantly associated with primary knee osteoarthritis in carriers of AA and AG genotypes of rs73123.