Supplementary Material for: Choroidal Thickening and Outer Retinal Alterations in Vitamin A Deficiency – A Case Report

Purpose: The purpose of this study was to report a case of retinal alterations due to proven Vitamin A deficiency. Methods: We report a case of a 39-year-old woman who presented with progressing nyctalopia and mildly reduced visual acuity over a period of 1-2 years, despite being on oral Vitamin A supplementation, following a history of gastric bypass and biliopancreatic diversion surgeries many years ago. Results: Vitamin A levels were severely reduced (<0.1 µmol/L, reference range: 1.05–2.08 µmol/L). The outer retinal layers exhibited structural alterations and a reduction in thickness, while choroidal thickness was increased. The electroretinogram showed complete depletion of scotopic responses and a mild reduction in photopic responses. After intravenous Vitamin A supplementation, complete resolution of both functional and structural changes was achieved. Conclusion: This case highlights the importance of considering Vitamin A deficiency even in patients receiving ongoing oral Vitamin A supplementation, particularly if symptoms and clinical findings suggest its presence. Choroidal thickening and outer retinal thinning may provide further insights into the pathophysiology of this condition in future analyses.