Related Experiment Video
Updated: May 27, 2026

Duodenal-Jejunal Bypass Surgery in Diet-Induced Obese Diabetic Mice
Published on: October 18, 2024
Daily vitamin supplementation and hypovitaminosis after obesity surgery
Simara Paganini Donadelli1, Márcia Varella Morandi Junqueira-Franco, Carlos Augusto de Mattos Donadelli
1Division of Nutrology, Department of Internal Medicine, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Objective:
The objective of this study was to determine whether constant daily vitamin supplementation would be sufficient to prevent possible vitamin deficiencies in obese patients undergoing bariatric surgery.
Methods:
The study was conducted on 58 men and women (mean age 41 ± 10 y) who underwent Roux-en-Y gastric bypass RYGB and were assessed preoperatively and at 3, 6, and 12 mo after surgery. During the postoperative period, the patients received a multivitamin-mineral supplement on a daily basis.
Results:
Serum β-carotene and vitamin C were lower starting from the third postoperative month and continued to be low after 12 mo, and vitamin A was decreased by the sixth month and increased by 12 mo. Vitamin B12 levels were stable up to 6 mo but were decreased by 12 mo. Folic acid levels increased from the third month and remained higher throughout follow-up. One year after surgery there were 19% and 21% increases in the number of patients with vitamin A and vitamin C deficiency, respectively, and a 4% decreased of patients with folic acid deficiency.
Conclusion:
Weight loss and improvement in patients' general condition followed surgery, but serum levels of some vitamins were decreased despite the use of a vitamin-mineral supplement. These patients need continuous follow-up and individualized prescription of supplementation after the surgical procedure to prevent and treat vitamin deficiencies.
Related Concept Videos
Drug Dosing: Obese Patients
Pharmacokinetics in Obese Patients: Drug Absorption and Distribution
Vitamins
Urinary Tract Calculi IV: Nutrition Therapy and Prevention
Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
Pharmacokinetics in Obese Patients: Drug Metabolism and Excretion