The Immunomodulatory Role of Vitamin D in Obesity
Abstract
Background
Obesity is fundamentally characterized by low-grade chronic inflammation (LGCI), driven by hypertrophic adipocytes and macrophage infiltration that release pro-inflammatory cytokines (e.g., TNF-α, IL-6). Vitamin D, recognized as a potent immunomodulator, holds significant potential in mitigating this inflammatory cascade. This review evaluates the impact of vitamin D supplementation on the pro-inflammatory cytokine profile and metabolic parameters in patients with obesity and metabolic syndrome.
Methods
A comprehensive literature review was conducted using PubMed and Google Scholar databases. The analysis encompassed 31 scientific articles, including recent meta-analyses and randomized controlled trials (RCTs), focusing on the interplay between vitamin D, systemic inflammation, and obesity-related metabolic disturbances.
Results
Current evidence indicates that vitamin D supplementation significantly reduces systemic inflammatory markers (IL-6, hs-CRP, TNF-α) and improves insulin resistance indices (HOMA-IR) and lipid profiles. However, supplementation alone does not induce significant reductions in body mass index (BMI) or total adipose tissue volume. Furthermore, owing to vitamin D sequestration in adipose tissue and volumetric dilution, patients with obesity require personalized, high-dose regimens (often ≥4,000 IU/day) to achieve optimal serum 25(OH)D levels (30–50 ng/mL) necessary for clinical immunomodulation.
Conclusions
While vitamin D is not a standalone weight-loss intervention, it serves as a crucial adjunctive therapy for modulating the LGCI associated with obesity. Current data do not support extrapolating these anti-inflammatory effects to a definitive reduction in cardiometabolic risk. However, achieving optimal serum levels requires personalized dosing to address altered pharmacokinetics, alongside essential lifestyle modifications, including diet and exercise.
© 2026 Wiktoria Górecka, Jakub Dudek, Aleksandra Dudek, Wiktoria Józefowicz, Dorota Szydłowska, published by The Medical Library named after S. Konopka in Warsaw
This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 License.