Long-term nutritional outcomes after bariatric surgery: A multicentre study by the Obesity and Metabolic Surgery Society of India

INTRODUCTION: This study aimed to examine the impact of metabolic and bariatric surgery (MBS) on key micronutrients in patients with obesity over 10 years. PATIENTS AND METHODS: A retrospective chart review was carried out for individuals who had MBS from February 2013 to May 2022 at 11 centres. The micronutrient (iron, Vitamin B12, Vitamin D3 and calcium) levels were collected before surgery and up to 10 years afterwards. RESULTS: The data from 1675 individuals with a mean age of 43.09 ± 11.93 years were analysed. The study population comprised 34.81% of males and 65.19% of females. There was an increase in the serum iron levels over 1 year (P < 0.01), 3 years (P < 0.01), 5 years (P = 0.2175), 7 years (P < 0.01) and 10 years (P = 0.0998) after surgery. Similar results were observed for Vitamin B12 levels at 1 year (P < 0.01), 3 years (P < 0.01), 5 years (P = 0.3083), 7 years (P = 0.2817) and 10 years (P = 0.2645). Vitamin D3 levels increased at 1 year (P < 0.01), 3 years (P < 0.01), 5 years (P < 0.01), 7 years (P = 0.0069) and 10 years (P = 0.8179). However, calcium levels exhibited a downwards trend at 5 years (P = 0.0008) post-surgery. CONCLUSIONS: A high prevalence of micronutrient deficiency was observed amongst patients preoperatively, which improved following MBS.