S5731 Zinc and Vitamin a Interdependence in Alcoholic Cirrhosis: A Case of Refractory Night Blindness

Introduction: Night blindness (nyctalopia) commonly reflects vitamin A deficiency, especially in alcoholic cirrhosis, where up to 50% of patients are deficient. Zinc is a critical cofactor for retinol‐binding protein (RBP) synthesis and for retinol dehydrogenase, and zinc deficiency, which is seen in roughly 70% of cirrhotic patients, can impair vitamin A mobilization and phototransduction. We describe a patient whose nyctalopia resolved only after correcting both deficiencies. Case Description/Methods: A 45-year-old man with decompensated alcoholic cirrhosis presented with 3 weeks of progressive difficulty seeing in dim light. He had no corneal lesions, a normal Schirmer’s test, an intact red reflex, and no macular pathology on fundus imaging. Baseline liver therapy included diuretics, lactulose, and vitamin B₁₂; alcohol abstinence was maintained. Serum retinol was severely low (< 0.02 mg/L), so oral vitamin A (25,000 IU/day) was initiated. After 4 weeks, nyctalopia persisted and impacted activities of daily living. Albumin was 3.0 g/dL which was not low enough to explain the nyctalopia. A review of literature suggested to suspect zinc deficiency. Serum zinc levels were ordered, and they measured 35.9 µg/dL (normal 60–120). Zinc acetate 50 mg thrice daily was added. Two weeks later, the patient reported complete resolution of night blindness; zinc was tapered to 20 mg/day for 3 months. Discussion: Dietary β-carotene and retinol absorption, hepatic storage (as retinyl esters in stellate cells), and release via RBP/pre-albumin complexes all depend on zinc. Zinc deficiency impairs RBP synthesis and retinol dehydrogenase activity, reducing delivery of 11-cis-retinal to photoreceptors. In cirrhosis, malnutrition, decreased RBP/pre-albumin synthesis, and alcohol’s direct effects on zinc homeostasis compound vitamin A deficiency. Our case underscores the interplay of zinc and vitamin A metabolism in alcohol-related liver disease and highlights the need to assess zinc status in cirrhotic patients with persistent nyctalopia despite vitamin A repletion.