OCULAR MANIFESTATIONS OF SYSTEMIC NUTRITIONAL DEFICIENCIES

Background: Systemic nutritional deficiencies are a significant yet underrecognized contributor to visual impairment and ocular disease globally. Vitamins such as A, D, and B12 are essential for maintaining the structural integrity and functional health of the eye. Deficiencies in these micronutrients are associated with a range of ophthalmic manifestations, from dry eye and night blindness to optic neuropathy. Despite their clinical relevance, nutritional causes of ocular symptoms are frequently overlooked in routine practice. Objective: This narrative review aims to explore the ocular manifestations of systemic deficiencies of vitamins A, D, and B12, synthesizing recent literature to highlight their pathophysiological effects, clinical presentations, and implications for patient care. Main Discussion Points: The review discusses the role of vitamin A in ocular surface maintenance and its deficiency-related conditions such as xerophthalmia and keratomalacia. Vitamin D is examined for its immunomodulatory function and links to inflammatory ocular conditions, including dry eye and uveitis. Vitamin B12 deficiency is reviewed in the context of optic neuropathy and its neuro-ophthalmic sequelae. Additionally, the review identifies methodological limitations in the current literature, inconsistencies in measurement outcomes, and a lack of standardized clinical guidelines. Conclusion: There is compelling evidence linking systemic nutritional deficiencies to distinct ocular pathologies. Early recognition and intervention can significantly alter disease progression and visual outcomes. However, further high-quality research is needed to standardize screening practices and refine therapeutic strategies.