vitamin-b-12 and Zollinger-Ellison-Syndrome

Proton pump inhibitors (PPI) are one of the most widely used classes of drugs. PPIs have a very favorable safety profile, and it is unusual for a patient to stop them because of side effects. However, with increasing numbers of patients chronically taking PPIs for gastroesophageal reflux disease and other common, persistent conditions, the long-term potential adverse effects are receiving increasing attention. An insufficiently studied area receiving much attention is the long-term effect of chronic acid suppression on the absorption of vitamins and nutrients. This increased attention results from the reported potential adverse effect of chronic PPI treatment leading to an increased occurrence of bone fractures. Interest in this area has led to examination of the effects of PPIs on calcium absorption/metabolism and numerous cohort, case-control, and prospective studies of their ability to affect bone density and cause bone fractures. In this article, these studies are systematically examined, as are studies of the effects of chronic PPI use on absorption of VB(12), iron, and magnesium. Studies in each area have led to differing conclusions, but when examined systematically, consistent results of several studies support the conclusion that long-term adverse effects on these processes can have important clinical implications.

Topics: Animals; Calcium; Fractures, Bone; Gastric Acid; Humans; Intestinal Absorption; Iron; Magnesium; Proton Pump Inhibitors; Vitamin B 12; Zollinger-Ellison Syndrome

Recent developments in our knowledge of the biochemistry and metabolism of cobalamin have given us some insight into clinical disorders. N2O, which easily induces cobalamin deficiency, both in vivo and in vitro, has greatly contributed to the investigation of the cobalamin deficient state, especially in relation to folate and amino acid metabolism. Demonstration of the cobalamin analog in human serum and a new enzyme which requires cobalamin as a coenzyme has led to recent increased interest in this field. The disorders of cobalamin metabolism will be summarized briefly as well as those areas currently of particular interest.

Topics: 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; Amino Acid Isomerases; Anemia, Pernicious; Animals; Diphyllobothriasis; DNA; Folic Acid; Humans; Intestinal Absorption; Intestinal Mucosa; Intramolecular Transferases; Malabsorption Syndromes; Methylmalonyl-CoA Mutase; Methyltransferases; Nervous System Diseases; Nitrous Oxide; Pancreatic Diseases; Thymidine Monophosphate; Vitamin B 12; Zollinger-Ellison Syndrome

Surgical procedures that lower portal pressure, such as portacaval shunts, prevent variceal hemorrhage. Portal hypertension is the result of increased flow and increased resistance in the portal system. Pharmacologic therapy is aimed at altering these factors by the use of vasoconstrictors to reduce flow and vasodilators to decrease resistance. The current status of pharmacologic agents to achieve these effects is reviewed.

Topics: Anemia, Pernicious; Autoimmune Diseases; Cell Membrane Permeability; Gastric Mucosa; Humans; Ileum; Intestinal Absorption; Intestinal Mucosa; Intrinsic Factor; Metabolic Diseases; Transcobalamins; Vitamin B 12; Zollinger-Ellison Syndrome

Topics: Absorption; Aged; Anemia, Pernicious; Animals; Biological Transport; Chemical Phenomena; Chemistry; Child; Diphyllobothriasis; Food Analysis; Humans; Intestinal Absorption; Intrinsic Factor; Malabsorption Syndromes; Nutritional Requirements; Stomach; Transcobalamins; Vitamin B 12; Vitamin B 12 Deficiency; Zollinger-Ellison Syndrome

Topics: Bile Acids and Salts; Biliary Fistula; Biliary Tract Diseases; Cholestyramine Resin; Chylomicrons; Colloids; Colonic Diseases; Feces; Gallbladder Diseases; Gastrointestinal Diseases; Humans; Intestinal Absorption; Intestinal Fistula; Intestinal Mucosa; Lipid Metabolism; Lipids; Liver Diseases; Macromolecular Substances; Malabsorption Syndromes; Neomycin; Pancreas; Solubility; Vitamin B 12; Xylose; Zollinger-Ellison Syndrome

Topics: Animals; Depression, Chemical; Dietary Fats; Digestion; Digestive System; Gastrins; Gastrointestinal Diseases; Humans; Intestinal Absorption; Intestinal Mucosa; Malabsorption Syndromes; Stimulation, Chemical; Vitamin B 12; Zollinger-Ellison Syndrome

Proton pump inhibitors (PPIs) may cause cyanocobalamin (vitamin B12) malabsorption, but measuring serum B12 alone may underestimate the prevalence. However, B12 deficiency elevates methylmalonic acid and homocysteine, both additional markers of B12 deficiency.. To determine the true prevalence of B12 deficiency and whether acid suppression by PPI caused it.. Sixty-one acid hypersecretors (basal acid output >15 mmol/h), 46 with gastrinoma [Zollinger-Ellison (ZE) syndrome] and 15 without [acid hypersecretor without gastrinoma (pseudo-ZE)], were treated with lansoprazole to determine its long-term (up to 18 years) pharmacological and clinical efficacy and safety, particularly as regards malabsorption of B12.. Of 61 patients, six (10%) had low serum B12. Additional tests uncovered B12 deficiency in 13 (31%) of 41 still-available patients, despite normal serum B12. B12 replacement reduced elevated homocysteine and methylmalonic acid, supporting the diagnosis. Also, measuring both basal and stimulated gastric secretion, we found that acid suppression was neither prolonged nor profound enough to explain the B12 deficiency.. In long-term recipients of PPIs, B12 deficiency was more frequent (29%) than detected by measuring only serum B12, and there was not enough acid suppression to explain this deficiency.

Topics: 2-Pyridinylmethylsulfinylbenzimidazoles; Female; Gastric Acid; Gastric Acidity Determination; Humans; Hydrogen-Ion Concentration; Lansoprazole; Male; Middle Aged; Proton Pump Inhibitors; Statistics as Topic; Time Factors; Vitamin B 12; Vitamin B 12 Deficiency; Zollinger-Ellison Syndrome

Long-term treatment with H(+)-K(+)-adenotriphosphatase (ATPase) inhibitors, such as omeprazole or lansoprazole, for severe gastroesophageal reflux disease is now widely used. Whether such treatment will result in vitamin B12 deficiency is controversial. We studied whether long-term treatment with omeprazole alters serum vitamin B12 levels in patients with Zollinger-Ellison syndrome.. In 131 consecutive patients treated with either omeprazole (n = 111) or histamine H2-receptor antagonists (n = 20), serum vitamin B12 and folate levels and complete blood counts were determined after acid secretion had been controlled for at least 6 months. These studies were repeated yearly. Serum vitamin B12 and folate levels were correlated with the type of antisecretory drug and the extent of inhibition of acid secretion.. The mean duration of omeprazole treatment was 4.5 years, and for H2-receptor antagonists 10 years. Vitamin B12 levels, but not serum folate levels or any hematological parameter, were significantly (P = 0.03) lower in patients treated with omeprazole, especially those with omeprazole-induced sustained hyposecretion (P = 0.0014) or complete achlorhydria (P < 0.0001). In 68 patients with two determinations at least 5 years apart, vitamin B12 levels decreased significantly (30%; P = 0.001) only in patients rendered achlorhydric. The duration of omeprazole treatment was inversely correlated with vitamin B12 levels (P = 0.013), but not folate levels. Eight patients (6%) developed subnormal B12 levels during follow-up.. Long-term omeprazole treatment leads to significant decreases in serum vitamin B12 but not folate levels. These results suggest patients with Zollinger-Ellison syndrome treated with H(+)-K(+)-ATPase inhibitors should have serum vitamin B12 levels monitored. Furthermore, these results raise the possibility that other patients treated chronically with H(+)-K(+)-ATPase inhibitors may develop B12 deficiency.

Topics: Achlorhydria; Adenosine Triphosphatases; Adolescent; Adult; Aged; Anti-Ulcer Agents; Drug Monitoring; Female; Folic Acid; Follow-Up Studies; Humans; Male; Middle Aged; Omeprazole; Time Factors; Vitamin B 12; Vitamin B 12 Deficiency; Zollinger-Ellison Syndrome

Topics: Dose-Response Relationship, Drug; Humans; Intestinal Absorption; Malabsorption Syndromes; Omeprazole; Time Factors; Vitamin B 12; Zollinger-Ellison Syndrome

Topics: Acid-Base Equilibrium; Gastrins; Humans; Hydrogen-Ion Concentration; Intestinal Absorption; Intestine, Small; Intrinsic Factor; Male; Middle Aged; Vitamin B 12; Zollinger-Ellison Syndrome

Topics: Antibodies; Celiac Disease; Chromatography, Thin Layer; Duodenum; Gastrectomy; Gastric Juice; Glucose Tolerance Test; Humans; Hydrogen-Ion Concentration; Intestinal Mucosa; Intrinsic Factor; Jejunum; Lipid Metabolism; Lipids; Microscopy, Electron; Pancreas; Schilling Test; Vitamin B 12; Zollinger-Ellison Syndrome

Topics: Absorption; Anemia; Anemia, Pernicious; Biomedical Research; Cobalt Isotopes; Electrophoresis; Gastrectomy; Gastric Juice; Humans; Intrinsic Factor; Radioisotopes; Radionuclide Imaging; Stomach; Urine; Vitamin B 12; Zollinger-Ellison Syndrome