Table 1: Complications and prevalence of nutritional deficits specified according to the particular type of bariatric surgical procedure.

Adjustable gastric band Roux-en-YDuodenal switch

Complications(i) Food intolerance or noncompliance(i) Anastomotic leak(i) Malabsorption of fat soluble vitamins (A, D, E, and K), iron
(ii) Band slippage which can result in vomiting leading to B1 deficiency(ii) Stomal stenosis can lead to vomiting(ii) Protein-energy malnutrition
(iii) Pouch dilatation(iii) Bowel obstruction
(iv) Band erosion into the stomach(iv) Micronutrient deficiencies
Vitamin AOccursOccursCommon: 50% after 1 yr, up to 70% after 4 yrs
Vitamin B1Rare but occursRare but occursRare but occurs
Vitamin B12UncommonCommon: 12–33%Rare but occurs
FolateUncommonUncommonUncommon
IronUncommonCommon: 20–49%Rare but occurs
CalciumUncommonMay occur: 10–25% by 2 yrs, 25–48% by 4 yrsMay occur: 10–25% by 2 yrs, 25–48% by 4 yrs
Vitamin DUncommonCommon: 17–52% by 2 yrs, 50–63% by 4 yrsCommon: 17–52% by 2 yrs, 50–63% by 4 yrs
Vitamin EUncommonUncommonUncommon
Vitamin KUncommonUncommonCommon: 50–60% after 1 year
CopperOccurs but often unrecognizedOccurs but often unrecognizedOccurs but often unrecognized