People with vitamin B-12 deficiency may have a variety of symptoms, including fatigue, nerve problems, and trouble thinking.  Diagnosis is typically based on blood levels of vitamin B12 below 120–180 pmol/L (170 to 250 pg/mL) in adults. Overall, an individual patient’s ability to absorb vitamin B12 is the most important factor in determining whether vitamin B12 should be administered orally or via injection . Medicine 1991;70:229-44. In one randomized, double-blind, placebo-controlled trial, 195 subjects aged 70 years or older with no or moderate cognitive impairment received 1,000 mcg vitamin B12, 1,000 mcg vitamin B12 plus 400 mcg folic acid, or placebo for 24 weeks . Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Evidence from retrospective, cross-sectional, and prospective studies links elevated homocysteine levels with coronary heart disease and stroke [50,53-62]. As a precaution, healthcare providers should monitor vitamin B12 status in patients taking proton pump inhibitors for prolonged periods . In moderate deficiency, soreness of the tongue, apthous ulcers, breathlessness, jaundice, hair fall and severe joint pain (arthralgia) may occur, and the beginning of neurological symptoms, including abnormal sensationssuch as pins and needles, numbness and tinnitus. Baillieres Clin Haematol 1995;8:639-55. During the physical examination, your doctor will look for a red, beefy tongue, pale or yellowish skin, a rapid pulse and heart murmurs resulting from an anemia-related increase in blood flow demands on the heart. [, Andrès E, Federici L, Affenberger S, Vidal-Alaball J, Loukili NH, Zimmer J, et al. It was discovered in 1934 that the volcanic soils lacked the cobalt salts essential for synthesis of vitamin B12 by their gut bacteria. FDA required manufacturers to use these new labels starting in January 2020, but companies with annual sales of less than $10 million may continue to use the old labels that list a vitamin B12 DV of 6.0 mcg until January 2021 [16,18]. Methionine is required for the formation of S-adenosylmethionine, a universal methyl donor for almost 100 different substrates, including DNA, RNA, hormones, proteins, and lipids. [, Seshadri S, Beiser A, Selhub J, Jacques PF, Rosenberg IH, D'Agostino RB, et al. J Clin Invest 1996;98:177-84. These drugs can interfere with vitamin B12 absorption from food by slowing the release of gastric acid into the stomach [87-89]. Expert Panel on Weight Loss Surgery, Executive Report, 2007. von Schenck U, Bender-Gotze C, Koletzko B. Persistence of neurological damage induced by dietary vitamin B12 deficiency in infancy. Vitamin B12 is required for proper red blood cell formation, neurological function, and DNA synthesis [1-5]. This includes some heartburn medicines including proton pump inhibitors (PPIs) such asÂ esomeprazoleÂ (Nexium), lansoprazoleÂ (Prevacid),Â omeprazoleÂ (Prilosec OTC),Â pantoprazoleÂ (Protonix), and rabeprazoleÂ (Aciphex), H2 Blockers such as cimetidine (Tagamet) andÂ famotidine (Pepcid AC); and certain diabetes medicines such as metformin (Glucophage). Diagnostic Accuracy of Holotranscobalamin, Vitamin B12, Methylmalonic Acid, and Homocysteine in Detecting B12 Deficiency in a Large, Mixed Patient Population. [, Flynn MA, Herbert V, Nolph GB, Krause G. Atherogenesis and the homocysteine-folate-cobalamin triad: do we need standardized analyses? Since your body doesn't make vitamin B12,Â you have to get it from animal-based foods or from supplements. For a reader-friendly overview of Vitamin B12, see our consumer fact sheet on Vitamin B12. ", Kaiser Permanente: "Vitamin B12 Deficiency Anemia. Vitamin B12 is a water-soluble vitamin that is naturally present in some foods, added to others, and available as a dietary supplement and a prescription medication. Once B12 reserves reach normal levels, injections of vitamin B12 will be needed every one to three months to prevent symptoms from returning. [, Monsen ALB, Ueland PM. Free vitamin B12 then combines with intrinsic factor, a glycoprotein secreted by the stomach's parietal cells, and the resulting complex undergoes absorption within the distal ileum by receptor-mediated endocytosis [5,7]. Clin Chem 1995;41:173-6.  However, the rate at which B12 levels may change when dietary intake is low depends on the balance between several variables.. Due to its role in energy metabolism, vitamin B12 is frequently promoted as an energy enhancer and an athletic performance and endurance booster.