Gastric Bypass

Gastric bypass, also known as Roux-en-Y gastric bypass (RYGB) is the most common form of bariatric surgery performed where the stomach is divided into a small upper pouch and a much larger lower "remnant" pouch and then the small intestine is rearranged to connect to both.

Nutrient deficiencies may arise due to:

  • Reduced dietary intake
  • Decreased capacity for digestion due to changes in stomach size
  • Micronutrient absorption impaired due to bypassing sections where absorption predominantly occurs

Source: Xanthakos, Stavra A. Nutritional Deficiencies in Obesity and After Bariatric Surgery. Pediatric clinics of North America 56.5 (2009): 1105–1121. PMC. Web. 25 Feb. 2017.

Post Operative Bariatric Nutrition: Gastric Bypass

Nutritional Deficiencies

Pre and Post Bariatric Surgery/Procedure
Pre-Surgery Post-Surgery
Protein X X
Calcium X
Vitamin A X X
Vitamin B1 (thiamin) X X
Vitamin B6 (pryidoxine) X X
Vitamin B12 (cobalamin) X X
Folate X X
Vitamin C X X
Vitamin E X  
Vitamin K    
Vitamin D X X
Iron   X
Zinc X X
Selenium X  
Copper   X

Nutritional deficiencies table shows deficiencies more commonly reported in research studies. For more information about deficiencies by procedure, and how these were identified, visit the resources section of Bariatric Advantage.