Abstract
Bariatric sleeve gastrectomy patients have 75% of their stomach removed, reducing the stomach volume and parietal cell mass, leaving a narrow gastric tube/sleeve. The parietal cell mass secretes hydrochloric acid and intrinsic factor, which are necessary for vitamin B12 absorption. A review of the literature indicates that a reduction in parietal cell mass could lead to a decline in serum B12 levels. A total of 72 sleeve gastrectomy patients between January 1, 2005, and December 31, 2007, were reviewed. Data collected by retrospective review until December 21, 2008, included gender, age, date of surgery, vitamin B12 supplementation, and serum B12 levels before and after surgery. Of the 72 patients, 27 patients were on B12 supplementation (38%) and 45 patients were not on supplementation (62%). Of the 45 patients not on supplementation: 24 had no postoperative B12 labs (53%), and four had no preoperative labs (9%). Seventeen (38%) had both pre- and postoperative B12 labs. The latest postoperative labs were reviewed from 0 to 39 months from date of surgery. Results of the 17 patients, using a paired t-test, showed that the average latest postoperative B12 level was 350 pg/mL±103 (247–453) compared to the average preoperative level of 394 pg/mL±148 (246–542) (p=0.04). Although B12 values were still within normal range, the study showed decline, which increases risk of nutritional deficiency over time with resultant irreversible neurological damage. A Pearson correlation demonstrated a negative trend, but it is not significant due to the small sample size. This study suggests that B12 labs should be performed routinely pre- and postoperatively. Further tests could be warranted to delineate a true B12 deficiency.
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