Endocrine Abstracts

Context: Bariatric surgery can lead to vitamin deficiencies.

Objective: To assess changes in blood vitamin concentrations after gastric bypass surgery.

Design: Twenty-nine patients underwent gastric bypass and 24 unmatched controls underwent lifestyle intervention in a prospective, non-randomised trial. Patients in the surgical group received multivitamin, iron, calcium, vitamin D, and vitamin B-12 supplements. No supplements were prescribed to the lifestyle group. Median BMI (kg/m²) decreased from 46 to 32 after surgery and from 40 to 39 after lifestyle intervention.

Results: Out of 53 included patients, 50 completed the 1-year follow-up (94%). Compared with lifestyle patients, the surgical patients had increased vitamin B-6, folic acid, vitamin B-12, and lipid-adjusted vitamin E (P<0.020 for each) concentrations; but decreased vitamin A concentrations (P<0.01) during follow-up. No significant difference between the groups was found for vitamin B-1, vitamin C, and 25-hydroxyvitamin D. Most surgical patients reported taking their supplements.

Conclusions: Gastric bypass patients adhering to a set of dietary supplements had mostly stable or increased vitamin concentrations, as compared both with their baseline values and with the changes in a non-surgical control group.

Ethics: The Regional Ethics Committee approved the study protocol. The trial was registered in ClinicalTrials.gov.