Micronutrients Deficiencies in Candidates of Bariatric Surgery: Results from a Single Institution over a 1-Year Period.

Preoperative micronutrient deficiencies were frequently found in candidates for BS. Approximately 90% of patients had deficient or insufficient serum levels of vitamin D preoperatively. Almost half of the patients had a preoperative deficit of folate, and vitamin B12 deficiency was significantly more frequent in the female population. It is mandatory to screen all patients undergoing BS for vitamin deficiencies before surgery.