Long-term iron and vitamin b12 deficiency are present after bariatric surgery, despite the widespread use of supplements

Mauro Lombardo, Arianna Franchi, Roberto Biolcati Rinaldi, Gianluca Rizzo, Monica D’adamo, Valeria Guglielmi, Alfonso Bellia, Elvira Padua, Massimiliano Caprio, Paolo Sbraccia

Research output: Contribution to journalArticlepeer-review


There are few long-term nutritional studies in subjects undergoing bariatric surgery that have assessed weight regain and nutritional deficiencies. 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 y, 42 females): 16 patients had Roux-en-Y gastric bypass (RYGB), 25 patients had sleeve gastrectomy (SG) and 11 subjects had adjustable gastric banding (AGB). All three bariatric procedures led to sustained weight loss: the average percentage excess weight loss, defined as weight loss divided by excess weight based on ideal body weight, was 60.6% ± 32.3. Despite good adherence to prescribed supplements, 80.7% of subjects (72.7%, AGB; 76.7%, SG; 93.8 %, 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%). Long-term nutritional deficiencies were greater than the general population among men for iron and among women for vitamin B12.

Original languageEnglish
Article number4541
Number of pages9
JournalInternational Journal of Environmental Research and Public Health
Issue number9
Publication statusPublished - May 1 2021


  • Adjustable gastric banding
  • Bariatric surgery
  • Iron
  • Nutritional deficiency
  • Roux-en-Y gastric bypass
  • Sleeve gastrectomy
  • Vitamin B12
  • Vitamin D

ASJC Scopus subject areas

  • Pollution
  • Public Health, Environmental and Occupational Health
  • Health, Toxicology and Mutagenesis


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