Vitamin A (Retinol) for Eye Health

Research suggests that vitamin A (retinol) plays a recognized role in eye health, particularly in relation to night blindness, a connection so well established in some communities that it has become the primary — and sometimes only — way people understand the nutrient's function, as documented in a 2025 cross-sectional survey from rural Bangladesh. A large 2023 genetic study using Mendelian randomization, the most methodologically rigorous source in this set, found evidence consistent with a causal relationship between circulating retinol levels and eye health outcomes, while also pointing to broader influences on inflammation, body composition, and brain structure. The remaining studies in this review are observational in nature and focused primarily on COVID-19 and immune function rather than eye health directly, meaning the evidence base here is narrow and does not include randomized controlled trials or meta-analyses specifically examining retinol's effects on vision outcomes. Overall, the available evidence is suggestive rather than definitive, and readers should be aware that most of these studies identify associations or genetic signals rather than confirmed cause-and-effect relationships in clinical populations.