Vitamin B12 deficiency

Devalia V, Hamilton MS, Molloy AM; British Committee for Standards in Haematology. Guidelines for the diagnosis and treatment of cobalamin and folate disorders. Br J Haematol. 2014 Aug;166(4):496-513.Full text  Abstract

Snow CF. Laboratory diagnosis of vitamin B12 and folate deficiency: a guide for the primary care physician. Arch Intern Med. 1999 Jun 28;159(12):1289-98.Full text  Abstract

Stabler SP. Clinical practice. Vitamin B12 deficiency. N Engl J Med. 2013 Jan 10;368(2):149-60. Abstract

National Institutes of Health, Office of Dietary Supplements. Dietary supplement fact sheet: vitamin B12. 2022 [internet publication].Full text

Guidelines and Protocols Advisory Committee, British Columbia. Cobalamin (vitamin B12) and folate deficiency. Jan 2023 [internet publication].Full text

1. Devalia V, Hamilton MS, Molloy AM; British Committee for Standards in Haematology. Guidelines for the diagnosis and treatment of cobalamin and folate disorders. Br J Haematol. 2014 Aug;166(4):496-513.Full text  Abstract

2. Snow CF. Laboratory diagnosis of vitamin B12 and folate deficiency: a guide for the primary care physician. Arch Intern Med. 1999 Jun 28;159(12):1289-98.Full text  Abstract

3. Tavares J, Baptista B, Gonçalves B, et al. Pernicious anaemia with normal vitamin B12. Eur J Case Rep Intern Med. 2019;6(2):001045.Full text  Abstract

4. Shah DR, Daver N, Borthakur G, et al. Pernicious anemia with spuriously normal vitamin B12 level might be misdiagnosed as myelodysplastic syndrome. Clin Lymphoma Myeloma Leuk. 2014 Aug;14(4):e141-3. Abstract

5. Yang DT, Cook RJ. Spurious elevations of vitamin B12 with pernicious anemia. N Engl J Med. 2012 May 3;366(18):1742-3.Full text  Abstract

6. Mazokopakis EE. Normal serum cobalamin levels do not exclude the diagnosis of pernicious anaemia: a case report. Fam Pract. 2020 Feb 19;37(1):1-3.Full text  Abstract

7. Wang Z, Zhu W, Xing Y, et al. B vitamins and prevention of cognitive decline and incident dementia: a systematic review and meta-analysis. Nutr Rev. 2022 Mar 10;80(4):931-49.Full text  Abstract

8. Chen H, Liu S, Ge B, et al. Effects of folic acid and vitamin B12 supplementation on cognitive impairment and inflammation in patients with Alzheimer's disease: a randomized, single-blinded, placebo-controlled trial. J Prev Alzheimers Dis. 2021;8(3):249-56. Abstract

9. Gil Martínez V, Avedillo Salas A, Santander Ballestín S. Vitamin supplementation and dementia: a systematic review. Nutrients. 2022 Feb 28;14(5):1033.Full text  Abstract

10. Tucker KL, Rich S, Rosenberg I, et al. Plasma vitamin B-12 concentrations relate to intake source in the Framingham Offspring study. Am J Clin Nutr. 2000 Feb;71(2):514-22. Abstract

11. Sukumar N, Saravanan P. Investigating vitamin B12 deficiency. BMJ. 2019 May 10;365:l1865. Abstract

12. Pennypacker LC, Allen RH, Kelly JP, et al. High prevalence of cobalamin deficiency in elderly outpatients. J Am Geriatr Soc. 1992 Dec;40(12):1197-204. Abstract

13. Clarke R, Grimley Evans J, Schneede J, et al. Vitamin B12 and folate deficiency in later life. Age Ageing. 2004 Jan;33(1):34-41.Full text  Abstract

14. Andres E, Loukili NH, Noel E, et al. Vitamin B12 (cobalamin) deficiency in elderly patients. CMAJ. 2004 Aug 3;171(3):251-9.Full text  Abstract

15. Pfisterer KJ, Sharratt MT, Heckman GG, et al. Vitamin B12 status in older adults living in Ontario long-term care homes: prevalence and incidence of deficiency with supplementation as a protective factor. Appl Physiol Nutr Metab. 2016 Feb;41(2):219-22. Abstract

16. Wong CW, Ip CY, Leung CP, et al. Vitamin B12 deficiency in the institutionalized elderly: A regional study. Exp Gerontol. 2015 Sep;69:221-5. Abstract

17. Mineva EM, Sternberg MR, Bailey RL, et al. Fewer US adults had low or transitional vitamin B12 status based on the novel combined indicator of vitamin B12 status compared with individual, conventional markers, NHANES 1999-2004. Am J Clin Nutr. 2021 Sep 1;114(3):1070-79.Full text  Abstract

18. Hunt A, Harrington D, Robinson S. Vitamin B12 deficiency. BMJ. 2014 Sep 4;349:g5226. Abstract

19. Allen LH. How common is vitamin B-12 deficiency? Am J Clin Nutr. 2009 Feb;89(2):693S-6S.Full text  Abstract

20. Björkegren K, Svärdsudd K. Serum cobalamin, folate, methylmalonic acid and total homocysteine as vitamin B12 and folate tissue deficiency markers amongst elderly Swedes - a population-based study. J Intern Med. 2001 May;249(5):423-32.Full text  Abstract

21. Yajnik CS, Deshpande SS, Lubree HG, et al. Vitamin B12 deficiency and hyperhomocysteinemia in rural and urban Indians. J Assoc Physicians India. 2006 Oct;54:775-82. Abstract

22. Fakhrzadeh H, Ghotbi S, Pourebrahim R, et al. Total plasma homocysteine, folate, and vitamin B12 status in healthy Iranian adults: the Tehran homocysteine survey (2003-2004)/a cross-sectional population based study. BMC Public Health. 2006 Feb 13;6:29.Full text  Abstract

23. Loikas S, Koskinen P, Irjala K, et al. Vitamin B12 deficiency in the aged: a population-based study. Age Ageing. 2007 Mar;36(2):177-83.Full text  Abstract

24. Madhari RS, Boddula S, Ravindranadh P, et al. High dietary micronutrient inadequacy in peri-urban school children from a district in South India: Potential for staple food fortification and nutrient supplementation. Matern Child Nutr. 2020 Dec;16 Suppl 3:e13065.Full text  Abstract

25. Pawlak R, Parrott SJ, Raj S, et al. How prevalent is vitamin B(12) deficiency among vegetarians? Nutr Rev. 2013 Feb;71(2):110-7.Full text  Abstract

26. Herrmann W, Schorr H, Obeid R, et al. Vitamin B-12 status, particularly holotranscobalamin II and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians. Am J Clin Nutr. 2003 Jul;78(1):131-6. Abstract

27. Weng TC, Chang CH, Dong YH, et al. Anaemia and related nutrient deficiencies after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis. BMJ Open. 2015 Jul 16;5(7):e006964.Full text  Abstract

28. Schijns W, Homan J, van der Meer L, et al. Efficacy of oral compared with intramuscular vitamin B-12 supplementation after Roux-en-Y gastric bypass: a randomized controlled trial. Am J Clin Nutr. 2018 Jul 1;108(1):6-12.Full text  Abstract

29. Rashid S, Meier V, Patrick H. Review of vitamin B12 deficiency in pregnancy: a diagnosis not to miss as veganism and vegetarianism become more prevalent. Eur J Haematol. 2021 Apr;106(4):450-5.Full text  Abstract

30. Sukumar N, Rafnsson SB, Kandala NB, et al. Prevalence of vitamin B-12 insufficiency during pregnancy and its effect on offspring birth weight: a systematic review and meta-analysis. Am J Clin Nutr. 2016 May;103(5):1232-51.Full text  Abstract

31. Jung SB, Nagaraja V, Kapur A, et al. Association between vitamin B12 deficiency and long-term use of acid-lowering agents: a systematic review and meta-analysis. Intern Med J. 2015 Apr;45(4):409-16. Abstract

32. Chapman LE, Darling AL, Brown JE, et al. Association between metformin and vitamin B12 deficiency in patients with type 2 diabetes: a systematic review and meta-analysis. Diabetes Metab. 2016 Nov;42(5):316-27. Abstract

33. Marino MC, de Olivera CA, Rocha AM, et al. Longterm effect of Helicobacter pylori eradication on plasma homocysteine in elderly patients with cobalamin deficiency. Gut. 2007 Apr;56(4):469-74.Full text  Abstract

34. Kaptan K, Beyan C, Ural AU, et al. Helicobacter pylori - is it a novel causative agent in vitamin B12 deficiency? Arch Intern Med. 2000 May 8;160(9):1349-53. Abstract

35. Lewerin C, Jacobsson S, Lindstedt G, et al. Serum biomarkers for atrophic gastritis and antibodies against Helicobacter pylori in the elderly: implications for vitamin B12, folic acid and iron status and response to oral vitamin therapy. Scand J Gastroenterol. 2008;43(9):1050-6. Abstract

36. Afsar MNA, Jhinu ZN, Bhuiyan MAI, et al. Helicobacter pylori infection and micronutrient deficiency in pregnant women: a systematic review and meta-analysis. BMJ Open Gastroenterol. 2020 Oct;7(1):e000490.Full text  Abstract

37. Aslan K, Bozdemir H, Unsal C, et al. The effect of anticonvulsant drugs on vitamin B12 metabolism. Int J Lab Hematol. 2008 Feb;30(1):26-35. Abstract

38. Linnebank M, Moskau S, Semmler A, et al. Antiepileptic drugs interact with folate and vitamin B12 serum levels. Ann Neurol. 2011 Feb;69(2):352-9.Full text  Abstract

39. Paulus MC, Wijnhoven AM, Maessen GC, et al. Does vitamin B12 deficiency explain psychiatric symptoms in recreational nitrous oxide users? A narrative review. Clin Toxicol (Phila). 2021 Nov;59(11):947-55.Full text  Abstract

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42. Stabler SP. Clinical practice. Vitamin B12 deficiency. N Engl J Med. 2013 Jan 10;368(2):149-60. Abstract

43. Sahu P, Thippeswamy H, Chaturvedi SK. Neuropsychiatric manifestations in vitamin B12 deficiency. Vitam Horm. 2022;119:457-70.Full text  Abstract

44. Arias PM, Domeniconi EA, García M, et al. Micronutrient deficiencies after Roux-en-Y gastric bypass: long-term results. Obes Surg. 2020 Jan;30(1):169-73.Full text  Abstract

45. Shankar P, Boylan M, Sriram K. Micronutrient deficiencies after bariatric surgery. Nutrition. 2010 Nov-Dec;26(11-12):1031-7. Abstract

46. Thompson WG, Wrathell E. The relation between ileal resection and vitamin B12 absorption. Can J Surg. 1977 Sep;20(5):461-4. Abstract

47. Duerksen DR, Fallows G, Bernstein CN. Vitamin B12 malabsorption in patients with limited ileal resection. Nutrition. 2006 Nov-Dec;22(11-12):1210-3. Abstract

48. Lederer AK, Hannibal L, Hettich M, et al. Vitamin B12 status upon short-term intervention with a vegan diet-a randomized controlled trial in healthy participants. Nutrients. 2019 Nov 18;11(11):2815.Full text  Abstract

49. Mazokopakis EE, Starakis IK. Recommendations for diagnosis and management of metformin-induced vitamin B12 (Cbl) deficiency. Diabetes Res Clin Pract. 2012 Sep;97(3):359-67. Abstract

50. Aroda VR, Edelstein SL, Goldberg RB, et al. Long-term metformin use and vitamin b12 deficiency in the diabetes prevention program outcomes study. J Clin Endocrinol Metab. 2016 Apr;101(4):1754-61.Full text  Abstract

51. Yang W, Cai X, Wu H, et al. Associations between metformin use and vitamin B12 levels, anemia, and neuropathy in patients with diabetes: a meta-analysis. J Diabetes. 2019 Sep;11(9):729-43. Abstract

52. de Jager J, Kooy A, Lehert P, et al. Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. BMJ. 2010 May 20;340:c2181.Full text  Abstract

53. Lam JR, Schneider JL, Zhao W, et al. Proton pump inhibitor and histamine 2 receptor antagonist use and vitamin B12 deficiency. JAMA. 2013 Dec 11;310(22):2435-42.Full text  Abstract

54. Pflipsen MC, Oh RC, Saguil A, et al. The prevalence of vitamin B12 deficiency in patients with type 2 diabetes mellitus: a cross-sectional study. J Am Board Fam Med. 2009 Sep-Oct;22(5):528-34.Full text  Abstract

55. Kim J, Ahn CW, Fang S, et al. Association between metformin dose and vitamin B12 deficiency in patients with type 2 diabetes. Medicine (Baltimore). 2019 Nov;98(46):e17918.Full text  Abstract

56. Finkelstein JL, Kurpad AV, Thomas T, et al. Vitamin B12 status in pregnant women and their infants in South India. Eur J Clin Nutr. 2017 Sep 12;71(9):1046-53. Abstract

57. Rogne T, Tielemans MJ, Chong MF, et al. Associations of maternal vitamin B12 concentration in pregnancy with the risks of preterm birth and low birth weight: a systematic review and meta-analysis of individual participant data. Am J Epidemiol. 2017 Feb 1;185(3):212-23.Full text  Abstract

58. National Institutes of Health, Office of Dietary Supplements. Dietary supplement fact sheet: vitamin B12. 2022 [internet publication].Full text

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60. Das JK, Salam RA, Mahmood SB, et al. Food fortification with multiple micronutrients: impact on health outcomes in general population. Cochrane Database Syst Rev. 2019 Dec 18;12:CD011400.Full text  Abstract

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64. Guidelines and Protocols Advisory Committee, British Columbia. Cobalamin (vitamin B12) and folate deficiency. Jan 2023 [internet publication].Full text

65. Hoey L, Strain JJ, McNulty H. Studies of biomarker responses to intervention with vitamin B-12: a systematic review of randomized controlled trials. Am J Clin Nutr. 2009 Jun;89(6):1981S-96S.Full text  Abstract

66. National Institute for Health and Care Excellence. Active B12 assay for diagnosing vitamin B12 deficiency. Sep 2015 [internet publication].Full text

67. Miller JW, Garrod MG, Rockwood AL, et al. Measurement of total vitamin B12 and holotranscobalamin, singly and in combination, in screening for metabolic vitamin B12 deficiency. Clin Chem. 2006 Feb;52(2):278-85.Full text  Abstract

68. Obeid R, Herrmann W. Holotranscobalamin in laboratory diagnosis of cobalamin deficiency compared to total cobalamin and methylmalonic acid. Clin Chem Lab Med. 2007;45(12):1746-50. Abstract

69. Valente E, Scott JM, Ueland PM, et al. Diagnostic accuracy of holotranscobalamin, methylmalonic acid, serum cobalamin, and other indicators of tissue vitamin b12 status in the elderly. Clin Chem. 2011 Jun;57(6):856-63.Full text  Abstract

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76. Lindenbaum J, Healton EB, Savage DG, et al. Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis. N Engl J Med. 1988 Jun 30;318(26):1720-8. Abstract

77. Savage DG, Lindenbaum J, Stabler SP, et al. Sensitivity of serum methylmalonic acid and total homocysteine determinations for diagnosing cobalamin and folate deficiencies. Am J Med. 1994 Mar;96(3):239-46. Abstract

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82. Sanz-Cuesta T, Escortell-Mayor E, Cura-Gonzalez I, et al. Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12). BMJ Open. 2020 Aug 20;10(8):e033687.Full text  Abstract

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85. Gomollón F, Gargallo CJ, Muñoz JF, et al. Oral cyanocobalamin is effective in the treatment of vitamin B12 deficiency in Crohn's disease. Nutrients. 2017 Mar 20;9(3):E308.Full text  Abstract

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95. Mahawar KK, Reid A, Graham Y, et al. Oral vitamin B12 supplementation after Roux-en-Y gastric bypass: a systematic review. Obes Surg. 2018 Jul;28(7):1916-23. Abstract

96. Homan J, Schijns W, Aarts EO, et al. An optimized multivitamin supplement lowers the number of vitamin and mineral deficiencies three years after Roux-en-Y gastric bypass: a cohort study. Surg Obes Relat Dis. 2016 Mar-Apr;12(3):659-67. Abstract

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101. Eussen SJ, de Groot LC, Clarke R, et al. Oral cyanocobalamin supplementation in older people with vitamin B12 deficiency: a dose-finding trial. Arch Intern Med. 2005 May 23;165(10):1167-72.Full text  Abstract

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