B-12 absorption may be altered to some degree after gastric bypass surgery, which can lead to B-12 deficiency and pernicious anemia in some people. Multivitamins typically contain B-12, but this may not prevent B-12 deficiency in all people after surgery. Treatment for B-12 deficiency will likely include B-12 supplemented sublingually or in some cases shots (usually monthly). Your doctor will let you know when you need this.
Prevention:
-Take your vitamins as directed.
-Be sure to come to all your scheduled follow-up appointments for lab tests. (lab tests can detect B-12 deficiency)
-Be sure to have your B-12 levels tested at least yearly after the first year following surgery.
(Information from WHMC Gastric Bypass Nutritional Guidelines Handbook)
