Clinlab Navigator

Nutritional Deficiencies Associated with Bariatric Surgery

Essential vitamins and nutrients are absorbed in the stomach, small intestine, and large intestine. Patients who have undergone bariatric surgery are at increased risk for vitamin deficiencies and are prescribed lifelong daily vitamin supplementation, which includes a multivitamin, vitamin B12, calcium citrate with vitamin D3, and vitamin D3 alone.

Roux-en-Y gastric bypass used to be the most common bariatric surgery, but has been surpassed by sleeve gastrectomy.  After bariatric surgery, the most common deficiencies are calcium, vitamin B12, and vitamin D. The least common deficiencies are vitamin B1 (thiamine), copper, and zinc. Copper deficiency occurs in 10 to 20% of patients who have undergone Roux-en-Y gastric by- pass, but is seldom reported after sleeve gastrectomy. Iron absorption is facilitated by vitamin C and is also limited by Roux-en-Y gastric bypass.


Bennett SE, et al. Case 22-2018: A 64-Year-Old Man with Progressive Leg Weakness, Recurrent Falls, and Anemia, New Engl J Med 2018;379:282-89.

Hansen EP, Metzsche C, Henningsen E, Toft P. Severe scurvy after gastric by- pass surgery and a poor postoperative diet. J Clin Med Res 2012;4:135-7. 

Parrott J, Frank L, Rabena R, Craggs- Dino L, Isom KA, Greiman L. American Society for Metabolic and Bariatric Surgery integrated health nutritional guidelines for the surgical weight loss patient 2016 update: micronutrients. Surg Obes Relat Dis 2017;13:727-41

AddThis Social Bookmark Button