Vitamin A supplementation in rheumatological diseases: A systematic review of the available clinical evidence

This review aims to identify and summarize the current evidence on the role of Vitamin A (Vit. A) in rheumatic diseases, focusing on its clinical and immunological effects. A comprehensive search of PubMed/MEDLINE and complementary databases was conducted to identify studies evaluating Vit. A in rheumatic diseases, covering the period from 1966 to May 2024. Relevant studies were reviewed and synthesized. The search revealed very limited human data; however, besides systemic lupus erythematosus (SLE), Vit. A–based interventions have also been evaluated in other rheumatologic contexts such as Sjögren’s syndrome and osteoarthritis (through a Vit. A–containing formulation). A small number of published studies assessed the effects of Vit. A supplementation or Vit. A-containing formulations, including two studies in SLE and additional evidence in Sjögren’s syndrome and osteoarthritis. Findings suggested potential immunological benefits, including modulation of cellular immune responses, with minimal reported adverse effects. In addition, Vit. A plays a recognized role in epithelial barrier integrity and host defense, suggesting a potential relevance for infection susceptibility in immunocompromised rheumatology patients. Overall, current evidence regarding the use of Vit. A in rheumatic diseases remains scarce, heterogeneous, and largely focused on lupus, despite limited data in other rheumatologic conditions. Further well-designed clinical studies are warranted to clarify its therapeutic relevance, safety profile, and potential role in infection susceptibility among patients with rheumatic diseases.