Long-Term Iron and Vitamin B12 Deficiency are Present After Bariatric Surgery, Despite the Widespread Use of Supplements.

Long-term nutritional studies in subjects undergoing bariatric surgery that have assessed weight regain and nutritional deficiencies are few. In this study, we report data 8 years after surgery on weight loss, use of dietary supplements and deficit of micronutrients in a cohort of patients from five centres in central and northern Italy. The study group consisted of 52 subjects (age: 38.1±10.6 yrs, 42 females): 16 patients had Roux-en-Y gastric bypass (RYGB), 25 patients sleeve gastrectomy (LSG) and 11 subjects adjustable gastric banding (AGB). All three bariatric procedures led to sustained weight loss: average percentage excess weight loss, defined as weight loss divided by excess weight based on ideal body weight was 60.6%±32.3. 80.7% of subjects (72.7%, AGB; 76%, SG; 93.7%, RYGB) reported at least one nutritional deficiency: iron (F 64.3% vs. M 30%), vitamin B12 (F 16.6% vs. M 10%), calcium (F 33.3% vs. M 0%) and vitamin D (F 38.1% vs. M 60%). Average weight loss was constant in RYGB and SG subjects from the third year after surgery. Long-term nutritional deficiencies were greater than the general population among men for iron and among women for vitamin B12.