Abstracts
1997 Digestive Disease Week

Are vitamin B-12 and folate deficiency clinically important after RY gastric bypass?

RE Brolin, JH Gorman, RC Gorman, AJ Petschenik, LJ Bradley, HA Kenler, RP Cody. UMDNJ-Robt W. Johnson Med Sch, New Brunswick, NJ.

Vitamin B-12 and folate deficiency are common after Roux-en-Y gastric bypass (RYGB) for morbid obesity. A CBC and serum levels of iron, TIBC, vitamin B-12 and folate were obtained preop and at regular intervals postop in 348 patients who had RYGB during a 10 yr period. The goals of this study were to learn how often patients had symptomatic deficiencies, the response rate to supplements of the deficient micronutrient and whether the risk of developing any deficiency decreases over time suggesting adaptation to malabsorption. All patients were told to take a multivitamin (MVI) supplement daily. Follow up was 42 ± 14 mo. Postop deficiencies were recognized in 268 of 348 patients (82%) including 155 (47%) with iron deficiency, 122 (37%) with vitamin B-12 deficiency, 115 (35%) with folate deficiency and 177 (54%) with anemia. Microcytic, hypochromic indicies were found in 63% of anemic patients. Only 3 patients (0.8%) had macrocytic indicies. No patient had macrocytic anemia. Hgb, Hct, and B-12 levels were significantly decreased vs. preop levels at all postop intervals. Conversely, folate was significantly increased vs. preop levels at all intervals. Iron and B-12 levels remained relatively stable postop. After 5 yrs. Hgb, Hct and B-12 were increased relative to values obtained between 3 and 5 yrs. postop. Iron deficiency was noted in 51% of females vs. 22% of males (p < 0.001). There was no gender difference in the incidence of either folate or B-12 deficiency. Taking MVI supplements resulted in a significantly lower incidence of folate deficiency but did not consistently prevent iron or B-12 deficiency. Oral iron and B-12 supplements corrected 43% and 81% of these deficiencies respectively. Folate deficiency was corrected with MVI supplements, alone. No patient had specific symptoms of B-12 or folate deficiency suggesting that these deficiencies are not clinically important after RYGB. Conversely, many patients had symptoms of iron deficiency anemia. On the basis of these findings prophylactic iron supplements are now provided to women who have RYGB. We no longer measure serum folate postop.