Supplement	LAGB	LSG and Roux‐en‐Y gastric bypass	BPD and duodenal switch
Standard multivitamin and mineral tablet including iron, folic acid, and thiamine	✔	✔	✔
1200–1500 mg elemental calcium	Optional, depending on serum levels	✔	✔
≥ 3000 IU of vitamin D, titrated to achieve normal serum levels	✔	✔	✔
Vitamin B12, titrated to achieve normal serum levels	Optional, depending on serum levels	✔	✔
Fat‐soluble vitamins (vitamins A, E, K)	Optional	Optional	✔

BPD = biliopancreatic diversion; IU = international units; LAGB = laparoscopic adjustable gastric band; LSG = laparoscopic sleeve gastrectomy.