Long-term prevalence of vitamin deficiencies after bariatric surgery: a meta-analysis.

backgroundBariatric surgery can lead to short-mid-term vitamin deficiencies, but the long-term vitamin deficiencies is unclear. This study aimed to conduct a meta-analysis regarding the long-term prevalence (≥ 5 years) of vitamin deficiencies after bariatric surgery.

methodsWe searched the EMBASE, PubMed, and CENTRAL databases for clinical studies until June 2023. Meta-analysis, sensitivity, subgroup, and meta-regression analyses were performed.

resultsThis meta-analysis included 54 articles with follow-up duration ranging from 5 to 17 years. The most prevalent vitamin deficiencies after surgery were vitamin D (35.8%), followed by vitamin E (16.5%), vitamin A (13.4%), vitamin K (9.6%), and vitamin B12 (8.5%). Subgroup analyses showed that the prevalence of vitamin A and folate deficiencies increased with the follow-up time. Roux-en-Y gastric bypass had a higher rate of vitamin B12 deficiency than sleeve gastrectomy and biliopancreatic diversion with duodenal switch (BPD-DS). Studies conducted in Europe had higher vitamin A deficiency (25.8%) than in America (0.8%); Asian studies had more vitamin B12 but less vitamin D deficiency than European and American studies. Meta-regression analysis displayed that publication year, study design, preoperative age, BMI, and quality assessment score were not associated with vitamin A, B12, D, and folate deficiencies rate.

conclusionA high prevalence of vitamin deficiencies was found after bariatric surgery in the long-term follow-up, especially vitamin D, E, A, K, and B12. The variation in study regions, surgical procedures, and follow-up time are associated with different postoperative vitamin deficiencies; it is necessary to develop more targeted vitamin supplement programs.