Vitamin B12

Vitamin B12 or also known as cyanocobalamin, is one of the eight B vitamins in B-complex. B12 helps to keep nerves and blood cells healthy, prevent megaloblastic anemia, and is important in the formation of DNA. The body absorbs this vitamin in two steps. The hydrochloric acid in the stomach separates the vitamin B12 from the food, and then the vitamin is combined with a stomach protein called intrinsic factor so that it can be absorbed properly.

Overall Health Benefits

  • Lowers risk of heart disease [1-10]
  • Lowers blood pressure [11-12]
  • Helps lose weight [13-15]
  • Prevents cancer [16-17]
  • Boosts brain power [18-25]
  • Prevents age-related blindness [26-27]

Difference between Methylcobalamin and Cyanocobalamin

Both methylcobalamin and cyanocobalamin are the main forms of vitamin B12. While they are nearly similar in structure, there are major differences between them.

Methylcobalamin is a naturally-occurring form of vitamin B12. It is bioidentical to the vitamin B12 forms that can be found in the body and various food sources. Methylcobalamin occurs in high amounts in organ meats, clams, sardines, beef, tuna, and shellfish. It can also be taken in the form of supplements. In contrast, cyanocobalamin, a synthetic form of vitamin B12 that is commonly used in food fortification, can be found only in supplements.

Another difference between methylcobalamin and cyanocobalamin is their absorption or bioavailability. Methylcobalamin has superior bioavailability compared to cyanocobalamin. This means that your body can absorb it better and it can raise your vitamin B12 levels faster.

Proven Health Benefits

Lowers Risk of Heart Disease

Studies suggest that vitamin B12 exerts cardioprotective effects:

  1. In patients with coronary artery disease (CAD), higher vitamin B12 levels were associated with a lower risk of heart disease. [1]
  2. A study found that low levels of vitamin B12 could lead to the development of CAD. [2]
  3. Studies found that vitamin B12 deficiency was associated with a higher risk of cardiovascular disease. [3-9]
  4. In patients who are at high risk for heart disease, vitamin B12 supplementation reduced cardiovascular disease risk by lowering homocysteine concentrations. [10]

Lowers Blood Pressure

Vitamin B12 has also been shown to protect against elevated blood pressure:

  1. In Japanese children, high vitamin B12 intakes resulted in lower blood pressure. [3]
  2. In Chinese rural adults, higher intake of vitamin B12 was associated with a lower risk of hypertension. [11]
  3. In elderly patients, vitamin B12 supplementation reduced blood pressure and arterial stiffness by lowering homocysteine levels. [12]

Helps Lose Weight

A number of studies found that vitamin B12 can help promote fat loss:

  1. In adult U.S citizens, higher vitamin B12 levels were associated with a lower risk of obesity. [13]
  2. In obese children and adolescents, higher intake of vitamin B12 promoted weight loss. [14]
  3. Vitamin B12 supplementation was also found to induce weight loss in obese subjects by lowering homocysteine levels. [15]

Prevents Cancer

Evidence suggests that vitamin B12 also has potent anti-cancer properties:

  1. A study showed that higher vitamin B12 levels can help lower the risk of gastric cancer. [16]
  2. A study also found a link between higher vitamin B12 intake and a lower colorectal cancer risk. [17]

Boosts Brain Power

Vitamin B12 is also essential for brain health according to studies:

  1. A study showed that adequate amounts of vitamin B12 can help maintain optimal brain function. [18]
  2. In a study conducted on aged individuals, a high level of vitamin B12 was found to be associated with an improved brain function. [19]
  3. A study also found that an adequate amount of vitamin B12 can help prevent various cognitive disorders. [20]
  4. Several human and animal studies showed that low vitamin B12 level in the brain was associated with the development of brain disorders. [21-25]

Prevents Age-Related Blindness

Studies also report that vitamin B12 is essential for optimal eye function and prevention of eye disorders

  1. In a clinical trial on adult females, vitamin B12 supplementation lowered the risk of age-related blindness. [26]
  2. A study found that vitamin B12 deficiency was related to poor vision in aging patients. [27]


  1. Mahalle N, Kulkarni MV, Garg MK, Naik SS. Vitamin B12 deficiency and hyperhomocysteinemia as correlates of cardiovascular risk factors in Indian subjects with coronary artery disease. J Cardiol. 2013 Apr;61(4):289-94. doi: 10.1016/j.jjcc.2012.11.009. Epub 2013 Mar 6. PMID: 23473764.
  2. Ma Y, Peng D, Liu C, Huang C, Luo J. Serum high concentrations of homocysteine and low levels of folic acid and vitamin B12 are significantly correlated with the categories of coronary artery diseases. BMC Cardiovasc Disord. 2017;17(1):37. Published 2017 Jan 21. doi:10.1186/s12872-017-0475-8.
  3. Tamai Y, Wada K, Tsuji M, Nakamura K, Sahashi Y, Watanabe K, Yamamoto K, Ando K, Nagata C. Dietary intake of vitamin B12 and folic acid is associated with lower blood pressure in Japanese preschool children. Am J Hypertens. 2011 Nov;24(11):1215-21. doi: 10.1038/ajh.2011.133. Epub 2011 Aug 4. PMID: 21814291.
  4. Hung J, Beilby JP, Knuiman MW, Divitini M. Folate and vitamin B-12 and risk of fatal cardiovascular disease: cohort study from Busselton, Western Australia. BMJ. 2003;326(7381):131. doi:10.1136/bmj.326.7381.131.
  5. Pawlak R. Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians? Am J Prev Med. 2015 Jun;48(6):e11-26. doi: 10.1016/j.amepre.2015.02.009. PMID: 25998928.
  6. Mahalle N, Kulkarni MV, Garg MK, Naik SS. Vitamin B12 deficiency and hyperhomocysteinemia as correlates of cardiovascular risk factors in Indian subjects with coronary artery disease. J Cardiol. 2013 Apr;61(4):289-94. doi: 10.1016/j.jjcc.2012.11.009. Epub 2013 Mar 6. PMID: 23473764.
  7. Kumar J, Garg G, Sundaramoorthy E, Prasad PV, Karthikeyan G, Ramakrishnan L, Ghosh S, Sengupta S. Vitamin B12 deficiency is associated with coronary artery disease in an Indian population. Clin Chem Lab Med. 2009;47(3):334-8. doi: 10.1515/CCLM.2009.074. PMID: 19676146.
  8. van Oijen MG, Laheij RJ, Jansen JB, Verheugt FW. The predictive value of vitamin B12 concentrations and hyperhomocysteinaemia for cardiovascular disease. Neth Heart J. 2007;15(9):291-294. doi:10.1007/BF03086002.
  9. Rafnsson SB, Saravanan P, Bhopal RS, Yajnik CS. Is a low blood level of vitamin B12 a cardiovascular and diabetes risk factor? A systematic review of cohort studies. Eur J Nutr. 2011 Mar;50(2):97-106. doi: 10.1007/s00394-010-0119-6. Epub 2010 Jun 29. PMID: 20585951.
  10. Abularrage CJ, Sidawy AN, White PW, Aidinian G, Dezee KJ, Weiswasser JM, Arora S. Effect of folic Acid and vitamins B6 and B12 on microcirculatory vasoreactivity in patients with hyperhomocysteinemia. Vasc Endovascular Surg. 2007 Aug-Sep;41(4):339-45.
  11. Liu R, Mi B, Zhao Y, Li Q, Yan H, Dang S. Effect of B Vitamins from Diet on Hypertension. Arch Med Res. 2017 Feb;48(2):187-194. doi: 10.1016/j.arcmed.2017.03.011. PMID: 28625322.
  12. van Dijk SC, Enneman AW, Swart KM, van Wijngaarden JP, Ham AC, Brouwer-Brolsma EM, van der Zwaluw NL, Blom HJ, Feskens EJ, Geleijnse JM, van Schoor NM, Dhonukshe-Rutten RA, de Jongh RT, Lips P, de Groot LC, Uitterlinden AG, Smulders YM, van den Meiracker AH, Mattace Raso FU, van der Velde N. Effects of 2-year vitamin B12 and folic acid supplementation in hyperhomocysteinemic elderly on arterial stiffness and cardiovascular outcomes within the B-PROOF trial. J Hypertens. 2015 Sep;33(9):1897-906; discussion 1906. doi: 10.1097/HJH.0000000000000647. PMID: 26147383.
  13. Sun Y, Sun M, Liu B, et al. Inverse Association Between Serum Vitamin B12 Concentration and Obesity Among Adults in the United States. Front Endocrinol (Lausanne). 2019;10:414. Published 2019 Jun 27. doi:10.3389/fendo.2019.00414.
  14. Pinhas-Hamiel O, Doron-Panush N, Reichman B, Nitzan-Kaluski D, Shalitin S, Geva-Lerner L. Obese Children and Adolescents: A Risk Group for Low Vitamin B12 Concentration. Arch Pediatr Adolesc Med. 2006;160(9):933–936. doi:10.1001/archpedi.160.9.933.
  15. Dixon, J B., et al. “Elevated Homocysteine Levels With Weight Loss After Lap-Band Surgery: Higher Folate and Vitamin B12 Levels Required to Maintain Homocysteine Level.” International Journal of Obesity and Related Metabolic Disorders : Journal of the International Association for the Study of Obesity, vol. 25, no. 2, 2001, pp. 219-27.
  16. Miranti EH, Stolzenberg-Solomon R, Weinstein SJ, et al. Low vitamin B12 increases risk of gastric cancer: A prospective study of one-carbon metabolism nutrients and risk of upper gastrointestinal tract cancer. Int J Cancer. 2017;141(6):1120-1129. doi:10.1002/ijc.30809.
  17. Sun, N., Huang, X., Wang, S., Li, Y., Wang, L., Wang, H., . . . Wang, Z. (2016). A dose–response meta-analysis reveals an association between vitamin B12 and colorectal cancer risk. Public Health Nutrition, 19(8), 1446-1456. doi:10.1017/S136898001500261X.
  18. Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy–A Review. Nutrients. 2016;8(2):68. Published 2016 Jan 27. doi:10.3390/nu8020068.
  19. Tangney CC, Aggarwal NT, Li H, et al. Vitamin B12, cognition, and brain MRI measures: a cross-sectional examination [published correction appears in Neurology. 2011 Nov 8;77(19):1773]. Neurology. 2011;77(13):1276-1282. doi:10.1212/WNL.0b013e3182315a33.
  20. Available at
  21. Shipton MJ, Thachil J. Vitamin B12 deficiency – A 21st century perspective . Clin Med (Lond). 2015;15(2):145-150. doi:10.7861/clinmedicine.15-2-145.
  22. Wolffenbuttel BHR, Wouters HJCM, Heiner-Fokkema MR, van der Klauw MM. The Many Faces of Cobalamin (Vitamin B12) Deficiency. Mayo Clin Proc Innov Qual Outcomes. 2019;3(2):200-214. Published 2019 May 27. doi:10.1016/j.mayocpiqo.2019.03.002.
  23. Pavlov CS, Damulin IV, Shulpekova YO, Andreev EA. Neurological disorders in vitamin B12 deficiency. Ter Arkh. 2019 May 16;91(4):122-129. doi: 10.26442/00403660.2019.04.000116. PMID: 31094486.
  24. Dubaj C, Czyż K, Furmaga-Jabłońska W. Vitamin B12 deficiency as a cause of severe neurological symptoms in breast fed infant – a case report. Ital J Pediatr. 2020 Mar 30;46(1):40. doi: 10.1186/s13052-020-0804-x. PMID: 32228659; PMCID: PMC7106665.
  25. Available at
  26. Christen WG, Glynn RJ, Chew EY, Albert CM, Manson JE. Folic acid, pyridoxine, and cyanocobalamin combination treatment and age-related macular degeneration in women: the Women’s Antioxidant and Folic Acid Cardiovascular Study. Arch Intern Med. 2009;169(4):335-341. doi:10.1001/archinternmed.2008.574.
  27. Available at

Success Stories

men testimonial before after

At the age of 60, I look and feel better than I ever have in my entire life! Switching my health program and hormone replacement therapy regimen over to Genemedics was one of the best decisions I’ve ever made in my life! Genemedics and Dr George have significantly improved my quality of life and also dramatically improved my overall health. I hav...
Nick Cassavetes ,60 yrs old Movie Director (“The Notebook”, “John Q”, “Alpha Dog”), Actor and Writer

Call 800-277-4041 for a Free Consultation

What to expect during your consultation:
  • Usually takes 15-30 minutes
  • Completely confidential
  • No obligation to purchase anything
  • We will discuss your symptoms along with your health and fitness goals
  • Free post-consult access for any additional questions you may have
Contact Us Page

Genemedics® Health Institute is a global premier institute dedicated to revolutionizing health and medicine through healthy lifestyle education, guidance and accountability in harmony with functional medicine. Our physician-supervised health programs are personally customized to help you reach your health and fitness goals while looking and feeling better than ever.