Among the most frequent 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 feminine 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. In addition, the women showed deficiency in folate at a higher lever (35% vs 22%). There was no difference in iron deficiency between the principal RYGBP and the revision group, however the revision group had significantly greater vitamin B12 deficiency. Going for a multivitamin supplement had no correlation with the development of iron or B12 deficiency; it did not prevent postoperative anemia, but it did decrease the incidence of folate deficiency. Patients who had low quantities of vitamin B12, iron, and folate were treated with either a multivitamin or with a product that addressed a particular deficiency. Taking iron supplements corrected only 43% of the iron deficiencies in this number of patients, whereas oral vitamin B12 supplements resulted in an 81% improvement rate. Taking the multivitamins usually corrected any folate deficiency. In a far more recent study of 30 patients who have been followed for a minimum of 24 months after surgery, the investigators concluded that “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 can be absorbed. RYGBP surgery creates a small gastric pouch that will not contain hydrochloric acid, then bypasses the percentage of the stomach and duodenum that secretes both pepsin and pancreatic enzymes that facilitate B12 binding to the “intrinsic factor.” The intrinsic factor is vital to the absorption of B12 in the distal portion of the tiny intestine. Postoperative iron deficiency arises from poor digestion of iron-containing foods, along with too little hydrochloric acid needed for proper absorption. As the portions of the tiny intestine (the duodenum and top of the area of the jejunum) where dietary iron is normally absorbed are bypassed during surgery, adequate absorption is prevented. Postoperative folate deficiency is somewhat less of a challenge because it may be absorbed in the remaining portions of the small intestine, although the possible lack of hydrochloric acid from the gastric pouch does impede the normal ability of the gut to absorb this nutrient.68 Patients who ate red meat less than once per week experienced significantly more iron, B12, and folate deficiency as in contrast to those that ate red meat more frequently.
The investigators figured reduction in red meat consumption post-RYGBP is really 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 for his or her premenopausal female RYGBP patients. Iron deficiency is the most common nutritional deficiency following RYGBP. The administration of an oral multivitamin supplement that features minerals might not be enough to stop iron deficiency or anemia in post-RYGBP patients; some may require IV administration to correct the problem. Menstruating women undergoing bariatric surgical procedure are specifically in danger 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 improve 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 numerous others: careful prophylactic nutritional postoperative follow-up is required for bariatric patients.