Nutritional Deficiencies as Modifiable Risk Factors for Postoperative Complications Following Abdominal Surgery

Abstract

Postoperative complications after abdominal surgery are a major source of perioperative morbidity and mortality. Preoperative nutritional deficiencies, particularly hypoalbuminemia, vitamin D insufficiency, and iron deficiency anemia, are prevalent, underrecognized, modifiable risk factors impairing wound healing and immune defense, yet routine nutritional assessment remains inconsistent. This narrative review synthesizes evidence on the independent and cumulative impact of preoperative hypoalbuminemia, vitamin D insufficiency, and anemia on postoperative complications after abdominal surgery, and outlines strategies for nutritional optimization. A literature search was conducted in June 2026 using PubMed/MEDLINE, PubMed Central, and the Cochrane Library for English-language studies from January 2010 to June 2026, including randomized trials, cohort studies, systematic reviews, and meta-analyses reporting surgical outcomes in adults undergoing abdominal procedures. Hypoalbuminemia was the most robustly supported risk factor, with pooled data showing an odds ratio of 2.37 for surgical site infection. Vitamin D insufficiency was independently associated with increased infectious complications, and preoperative anemia contributed to tissue hypoxia, impaired collagen synthesis, and immune dysfunction. Co-occurring deficiencies were associated with cumulative impairment of immune and reparative function. Hypoalbuminemia, vitamin D insufficiency, and anemia are prevalent, mechanistically distinct, clinically significant modifiable risk factors for postoperative complications after abdominal surgery. Routine screening with validated tools and targeted laboratory evaluation is strongly supported by current evidence.