Vitamin B12

Among other functions, Vitamin B12 or cobalamin assists in the synthesis of neurotransmitters, DNA, phospholipids, and helps metabolize fatty and amino acids in cells. It is found is fish, fortified cereals, meat, poultry, and can also be made in a laboratory. It has various health benefits and is used to treat ailments and diseases like pernicious anemia, reduce homocysteine levels, and helps reduce the risk of certain types of cancer.

Vitamin B12 and Cancer

  • Many studies have found that an increased intake of vitamin B12, folate, and vitamin B6 can lower the risks of breast cancer and cervical cancer.
  • However, it is not effective for lung cancer. On the contrary, some studies suggest that a long-term use of vitamin B12 supplements can increase the risk of lung cancer, especially in older men.
  • In another study, it was found that a dietary intake of vitamin B12 and folate during pregnancy lowers the risk of acute lymphoblastic leukemia in children. However, this needs to be confirmed by further studies.
  • For the non-small cell lung cancer patients undergoing pemetrexed chemotherapy, intra-muscular injections of vitamin B12 and oral folic acid can reduce the toxicity of the therapy and can also improve the efficacy of the treatment. This is not achieved if vitamin B12 is taken orally. 


  • Vitamin B-50 Complex – 60 Capsules by Nature’s Way – Amazon Link
  • NOW Vitamin B-50 mg,100 Tablets – Amazon Link
  • Spring Valley – Vitamin B-Complex B50, Timed Release, 60 Tablets – Amazon Link
  • Inlife Vitamin B12 (Methylcobalamin) Ala & Folic Acid Supplements 1500 Mcg – 60 Tablets – Amazon Link

References & More Information

  1. Credit: Beyond Conventional Care Therapies
  2. Integrative Oncology Cancer Care
  3. Lajous M, Lazcano-Ponce E, Hernandez-Avila M, et al. Folate, vitamin B(6), and vitamin B(12) intake and the risk of breast cancer among Mexican women. Cancer Epidemiol Biomarkers Prev. Mar 2006;15(3):443-448. doi: 10.1158/1055-9965.EPI-05-0532
  4. Shrubsole MJ, Jin F, Dai Q, et al. Dietary folate intake and breast cancer risk: results from the Shanghai Breast Cancer Study. Cancer Res. Oct 1 2001;61(19):7136-7141
  5. Zhang SM, Willett WC, Selhub J, et al. Plasma folate, vitamin B6, vitamin B12, homocysteine, and risk of breast cancer. J Natl Cancer Inst. Mar 5 2003;95(5):373-380
  6. Hernandez BY, McDuffie K, Wilkens LR, et al. Diet and premalignant lesions of the cervix: evidence of a protective role for folate, riboflavin, thiamin, and vitamin B12. Cancer Causes Control. Nov 2003;14(9):859-870
  7. Hartman TJ, Woodson K, Stolzenberg-Solomon R, et al. Association of the B-vitamins pyridoxal 5’-phosphate (B(6)), B(12), and folate with lung cancer risk in older men. Am J Epidemiol. Apr 1 2001;153(7):688-694
  8. Brasky TM, White E, Chen CL. Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort. J Clin Oncol. 2017 Aug 22:JCO2017727735. doi: 10.1200/JCO.2017.72.7735. Epub 2017 Aug 22.
  9. Bailey HD, Miller M, Langridge A, et al. Maternal dietary intake of folate and vitamins B6 and B12 during pregnancy and the risk of childhood acute lymphoblastic leukemia. Nutr Cancer. 2012;64(7):1122-1130
  10. Ohe Y, Ichinose Y, Nakagawa K, et al. Efficacy and safety of two doses of pemetrexed supplemented with folic acid and vitamin B12 in previously treated patients with non-small cell lung cancer. Clin Cancer Res. Jul 1 2008;14(13):4206-4212. doi: 10.1158/1078-0432.CCR-07-5143
  11. Yang TY, Chang GC, Hsu SL, et al. Effect of folic acid and vitamin B12 on pemetrexed antifolate chemotherapy in nutrient lung cancer cells. Biomed Res Int. 2013;2013:389046. doi: 10.1155/2013/389046
  12. Scagliotti GV, Shin DM, Kindler HL, et al. Phase II study of pemetrexed with and without folic acid and vitamin B12 as front-line therapy in malignant pleural mesothelioma. J Clin Oncol. Apr 15 2003;21(8):1556-1561. doi: 10.1200/JCO.2003.06.122
  13. Takagi Y, Hosomi Y, Nagamata M, et al. Phase II study of oral vitamin B12 supplementation as an alternative to intramuscular injection for patients with non-small cell lung cancer undergoing pemetrexed therapy. Cancer Chemother Pharmacol. Mar 2016;77(3):559-564
  14. Natural sources of Vitamin E by Doctors Beyond Medicines

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