# Oxidative Stress, Micronutrient Deficiencies and Coagulation Disorders After Bariatric Surgery: A Systematic Review

## TL;DR

This review explores how bariatric surgery affects blood clotting, oxidative stress, and nutrient levels, highlighting risks and the need for monitoring.

## Contribution

The study systematically reviews the link between bariatric surgery, oxidative stress, micronutrient deficiencies, and coagulation disorders.

## Key findings

- Micronutrient deficiencies after bariatric surgery impair antioxidant defenses and coagulation pathways.
- Persistent redox imbalance and elevated D-dimer or vWF are observed in some patients post-surgery.
- Vitamin K deficiency and malabsorptive procedures are linked to bleeding and clotting complications.

## Abstract

Metabolic bariatric surgery (MBS) induces substantial metabolic, inflammatory, and nutritional changes that can alter hemostatic balance through redox-dependent mechanisms. This systematic review evaluated coagulation disturbances after MBS with emphasis on oxidative stress and micronutrient deficiencies. A structured search of PubMed, Scopus, and Web of Science (2000–2025) identified 1707 records; 21 studies met inclusion criteria. Available evidence suggests that although MBS reduces obesity-related inflammation and oxidative burden in many patients, a proportion of individuals may present with persistent redox imbalance, elevated D-dimer or vWF (von Willebrand Factor), and delayed normalization of fibrinolysis. Micronutrient deficiencies—particularly vitamins K, B12, folate, selenium, zinc, and copper—are common after malabsorptive procedures and contribute to both thrombotic and hemorrhagic complications by impairing antioxidant defenses, endothelial function, and vitamin K-dependent coagulation pathways. Postoperative venous thromboembolism (VTE) incidence ranges from 0.3 to 0.5%, with higher risk after Roux-en-Y gastric bypass than sleeve gastrectomy, while bleeding is primarily associated with vitamin K deficiency, marginal ulcers, and anticoagulant exposure. The findings underscore the interdependence of oxidative stress, nutritional status, and hemostasis after MBS. Individualized thromboprophylaxis, routine detection of micronutrient deficiencies, and long-term biochemical monitoring are essential to maintain hemostatic stability. Standardized redox–hemostasis biomarker panels are needed to clarify mechanistic pathways and improve postoperative preventive strategies.