Prevalence, Ocular Manifestations, and Treatment Response in Post-Bariatric Vitamin A Deficiency: A Systematic Review...

To estimate procedure-specific prevalence of biochemical vitamin A deficiency after bariatric surgery and synthesize ocular manifestations, postoperative latency, and response to vitamin A repletion.

As bariatric surgery volume continues to rise, recognition of procedure-specific vitamin A deficiency and its ocular manifestations may improve ophthalmic surveillance, earlier diagnosis, and timely repletion in post-bariatric patients.

Following PROSPERO registration (CRD420261329094), we did a systematic review of MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Scopus, and Web of Science through March 2026 for studies reporting vitamin A status or ocular manifestations after bariatric surgery. Risk of bias was evaluated with the Cochrane RoB 2, ROBINS-I, and Joanna Briggs Institute checklists; the overall certainty of evidence was assessed with the GRADE framework.

Of 1,574 abstracts screened, 27 reports representing 21 unique studies met inclusion criteria; 18 contributed quantitative data, of which 9 nonpregnancy surveillance cohorts (455 tested participants) entered the prevalence meta-analysis. Prevalence was 18.0% after Roux-en-Y gastric bypass (RYGB), 59.0% after biliopancreatic diversion (BPD), 37.8% after BPD with duodenal switch (BPD-DS), and 42.5% after jejunoileal bypass (JIB); the pooled estimate across these heterogeneous procedures and study-defined retinol thresholds was 26.1% (95% CI, 18.5-35.4), reported as a secondary summary. Pregnancy-specific post-RYGB prevalence was 63.3% (95% CI, 43.9-80.1). Night blindness prevalence was 60.1% in active/formal non-overlapping cohorts with symptom denominators. Median latency to ocular presentation was 5 years after RYGB and 14 to 27 years after BPD-DS, JIB, or revisional procedures (19 patients). Among 14 post-bariatric treatment-response records with assessable ocular outcomes, 13 (93%) improved or resolved.

Among the procedures with adequate data, vitamin A deficiency is procedure-specific and common during pregnancy after RYGB. Ocular disease may present years to decades after surgery, but often improves when deficiency is recognized and treated. Certainty was limited by heterogeneity, the small number of cohorts for some procedure subgroups, and selective reporting of ocular outcomes. Nyctalopia, ocular surface disease, atypical outer retinal findings, or unexplained visual decline in a post-bariatric patient warrant prompt serum retinol testing and coordinated nutritional management regardless of the interval since surgery.