Background/Objectives: Chronic low-grade inflammation and nutritional deficiencies, particularly vitamin D deficiency, have emerged as important contributors to Metabolic syndrome (MetS) pathogenesis but remain underexplored. This study aimed to comprehensively evaluate the associations between dietary intake, vitamin D status, and inflammatory biomarkers (high-sensitivity C-reactive protein -CRP- and ferritin) in patients with MetS. Methods: A cross-sectional observational study was conducted on 141 adult MetS patients at a Mexican hospital. Clinical, anthropometric, dietary (using a validated food frequency questionnaire), and biochemical data including serum 25-hydroxyvitamin D, CRP, ferritin, and neutrophil-to-lymphocyte ratio (NLR) were collected. Vitamin D deficiency was defined as serum 25(OH)D 14.3 g/dL associated with hyperferritinemia, it did not independently predict CRP in multivariate analyses. Frequent consumption of vitamin D-rich foods (milk, fish, Manchego and Oaxaca cheese) was associated with lower inflammation. Mediation analysis confirmed that vitamin D deficiency mediated dietary intake-CRP and dietary intake-ferritin links (Sobel test p < 0.05). Conclusions: Vitamin D deficiency is a key mediator linking inadequate dietary vitamin D intake to systemic inflammation in MetS. Nutritional strategies emphasizing vitamin D repletion and consumption of vitamin D fortified foods may effectively reduce chronic inflammation and improve metabolic outcomes.
Cortes-Álvarez et al. (Sat,) studied this question.