Among the most common nutritional deficiencies after RYGBP procedures are iron, folic acid (vitamin B9), and cobalamin (vitamin B12).66,67 In 1998, Brolin and associates68 investigated B12 and folate deficiency in several 348 postRYGBP patients over a period of 10 years, 7.7% of whom had revision procedures. Nutrient deficiencies were within 82% of the patients in the immediate postoperative period: 47% had iron deficiency, 37% had vitamin B12 deficiency, 35% had folate deficiency, and 54% were anemic; 51% of the female patients and 22% of the male patients had iron deficiency. No gender differences were noted for vitamin B12 or anemia, although the women had significantly lower iron saturation levels. Anemia became evident in the men 29 months postoperatively—almost 2 years later than in the women. Additionally, the ladies showed deficiency in folate at a higher lever (35% vs 22%). There was no difference in iron deficiency between the primary RYGBP and the revision group, nevertheless the revision group had significantly greater vitamin B12 deficiency. Having a multivitamin supplement had no correlation with the development of iron or B12 deficiency; it didn’t prevent postoperative anemia, but it did decrease the incidence of folate deficiency. Patients who’d low degrees of vitamin B12, iron, and folate were treated with whether multivitamin or with a complement that addressed a certain deficiency. Taking iron supplements corrected only 43% of the iron deficiencies in this band of patients, whereas oral vitamin B12 supplements resulted in an 81% improvement rate. Taking the multivitamins usually corrected any folate deficiency. In a more recent study of 30 patients who have been followed for at the least 24 months after surgery, the investigators figured “vitamin supplementation isn’t sufficient to prevent iron and vitamin B12 deficiencies in many patients.”69 As vitamin B12 is bound to protein, it must be cleaved by digestive enzymes (pepsin and hydrochloric acid) before it could be absorbed. RYGBP surgery creates a small gastric pouch that doesn’t contain hydrochloric acid, then bypasses the part of the stomach and duodenum that secretes both the pepsin and pancreatic enzymes that facilitate B12 binding to the “intrinsic factor.” The intrinsic factor is important to the absorption of B12 in the distal part of the tiny intestine. Postoperative iron deficiency comes from poor digestion of iron-containing foods, as well as a lack of hydrochloric acid necessary for proper absorption. Since the portions of the small intestine (the duodenum and top of the part of the jejunum) where dietary iron is usually absorbed are bypassed during surgery, adequate absorption is prevented. Postoperative folate deficiency is somewhat less of a problem because it may be absorbed in the rest of the portions of the tiny intestine, although the lack of hydrochloric acid from the gastric pouch does impede the standard ability of the gut to absorb this nutrient.68 Patients who ate red meat less than once weekly experienced far more iron, B12, and folate deficiency as weighed against people who ate red meat more frequently.
The investigators figured decrease in red meat consumption post-RYGBP is a major contributing factor to the development of iron and B12 deficiencies.63 Patients who disregard the pre- and postoperative nutrition instructions given by surgical support teams invariably develop micronutrient deficiencies. Of the three deficiencies identified by Brolin and associates,68 only iron deficiency and the accompanying anemia caused symptoms (feeling weak and tired) of which the patients were aware; 93.5% of the patients who developed anemia were female. The investigators figured vitamin B12 and folate deficiency were not clinically important after RYGBP surgery, but iron deficiency and anemia were. They recommend 50 mg elemental iron supplements because of their premenopausal female RYGBP patients. Iron deficiency is the most common nutritional deficiency following RYGBP. The administration of an oral multivitamin supplement that includes minerals might not be enough to avoid iron deficiency or anemia in post-RYGBP patients; some may require IV administration to fix the problem. Menstruating women undergoing bariatric surgical procedure are specifically at an increased risk for development of iron deficiency and resultant anemia. Preoperative assessment of bariatric surgery patients will include an entire hematologic work-up. These patients require lifelong monitoring of iron, B12, and folate levels to fix any discovered discrepancy rapidly and definitively.70 Marinella71 reviewed all possible causative factors in the development of varied anemias in the postoperative bariatric surgery patient. Included were surgical blood loss, stomal ulcerations, and deficiencies in vitamin B12, folate, thiamine, riboflavin, niacin, pyridoxine, vitamin C, copper, and protein. The investigator’s conclusions supported those of several others: careful prophylactic nutritional postoperative follow-up is required for bariatric patients.