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Vitamin B12 (Cyanocobalamin)
It is a water-soluble hematopoietic (necessary for manufacture of red blood cells) vitamin occurring in meats and animal products. To be absorbed by the intestine, B12 must combine with intrinsic factor, and its metabolism is interconnected with that of folic acid. The vitamin is necessary for the growth and replication of all body cells and the functioning of the nervous system. Deficiency of vitamin B12 causes pernicious anemia and other forms of megaloblastic anemia, and neurologic lesions.

Vitamin B12 is stored in the liver. A healthy adult has a large reserve supply of B12 available, and B12 levels tend to change slowly.

We recommend that our patients take sublingual B12, 1000 micrograms per week. Sublingual means "under the tongue". B12 supplements that are swallowed don't get absorbed well. Sublingual preparations are in a crystalline form and can be absorbed directly into the blood stream through the tissues under the tongue.

Your B12 level can be checked with a blood test. We recommend that your level be tested every six months so that you can be sure that you have enough of this important vitamin.

The following abstracts were gathered from the medical literature. To search for others: PubMed.

Are vitamin B12 and folate deficiency clinically important after roux-en-Y gastric bypass?

Brolin RE, Gorman JH, Gorman RC, Petschenik AJ, Bradley LJ, Kenler HA, Cody RP

Although iron, vitamin B12, and folate deficiency have been well documented after gastric bypass operations performed for morbid obesity, there is surprisingly little information on either the natural course or the treatment of these deficiencies in Roux-en-Y gastric bypass (RYGB) patients. During a 10-year period, a complete blood count and serum levels of iron, total iron-binding capacity, vitamin B12, and folate were obtained in 348 patients preoperatively and postoperatively at 6-month intervals for the first 2 years, then annually thereafter. The principal objectives of this study were to determine how readily patients who developed metabolic deficiencies after Roux-en-Y gastric bypass responded to postoperative supplements of the deficient micronutrient and to learn whether the risk of developing these deficiencies decreases over time.Hemoglobin and hematocrit levels were significantly decreased at all postoperative intervals in comparison to preoperative values. Moreover, at each successive interval through 5 years, hemoglobin and hematocrit were decreased significantly compared to the preceding interval. Folate levels were significantly increased compared to preoperative levels at all time intervals. Iron and vitamin B12 levels were lower than preoperative measurements and remained relatively stable postoperatively. Half of the low hemoglobin levels were not associated with iron deficiency. Taking multivitamin supplements resulted in a lower incidence of folate deficiency but did not prevent iron or vitamin B12 deficiency. Oral supplementation of iron and vitamin B12 corrected deficiencies in 43% and 81% of cases, respectively. Folate deficiency was almost always corrected with multivitamins alone. No patient had symptoms that could be attributed to either vitamin B12 or folate deficiency Conversely, many patients had symptoms of iron deficiency and anemia. Lack of symptoms of vitamin B12 and folate deficiency suggests that these deficiencies are not clinically important after RYGB. Conversely, iron deficiency and anemia are potentially serious problems after RYGB, particularly in younger women. Hence we recommend prophylactic oral iron supplements to premenopausal women who undergo RYGB.

J Gastrointest Surg 1998 Sep-Oct;2(5):436-42

Late effects of gastric bypass for obesity.

Crowley LV, Seay J, Mullin G.

We studied 41 patients who had gastric bypass for obesity from 1974-1979. The procedure was well received by patients and most achieved adequate weight loss, but most subjects consumed inadequate diets and many developed iron and/or vitamin B12 deficiencies. Ten were anemic and 13 had been treated previously for postbypass anemia. Severely vitamin B12-deficient subjects did not respond to 50 micrograms oral vitamin B12 tablets, but those with milder deficiencies usually did. Schilling tests were usually abnormal and corrected when intrinsic factor was given. Many subjects developed manifestations compatible with osteoporosis due to inadequate calcium intake and absorption, and some also developed abnormal laboratory tests suggesting coexisting osteomalacia. Hematopoietic complications of gastric bypass can usually be prevented and are relatively easy to treat, but musculoskeletal complications may be more difficult to prevent and treat.

Am J Gastroenterol 1984 Nov;79(11):850-60

Thus we suggest that all patients take supplemental B12, Iron, and Calcium.


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