Vitamin B12: Could It Be a Promising Immunotherapy?

Abstract

Vitamin B12 is a water-soluble vitamin and an important micronutrient with critical role in DNA, protein, and lipid synthesis. It is responsible for one-carbon metabolism and cell division of nervous and hematopoietic cells. Among its various functions, the role as immunomodulator in cellular immunity, especially in elevating the number of CD8+ cells and NK cells, atracts scientiic interest. Many alternative anticancer and anti-inlammatory treatments involve the use of B12 together with other vitamins and nutrients, but still the scientiic information is too obscure and insuicient. Controversial data link tumorigenesis with either increased or decreased B12 blood levels in diferent types of cancer. Dietary intake and additional supplement with the vitamin do not protect against cancer risk, but the dominant opinion is to integrate B12 as part of rational and healthy nutrition to ensure proper function of the immune system. This chapter will review in brief the most important facts for vitamin B12 functions and properties. We will try also to present in concise way the human immune system and the exact role of B12 in immune activity with emphasis on the questionable participation of vitamin B12 in the process of carcinogenesis and its signiicance as anticancer immunotherapy.Keywords: vitamin B12, immunonutrition, immunomodulation, immunotherapy, tumorigenesis, cancer, inlammation IntroductionCancer is the inal outcome of uncontrolled overgrowth of normal cells. Cancer cells remain insensitive to antiproliferative signals and apoptosis. As a result, they replicate, proliferate, and invade ininitely and aggressively. Although the genetic events are thought to be the most important in the process of carcinogenesis, other factors can facilitate abnormal cell development. For many years, inlammation and anti-inlammatory response were widely associated with malignancy [1, 2] and recognized as major elements that trigger carcinogenesis.© 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Extended inlammation, especially in chronic infections, predisposes to cancer, but still the mechanism(s) involved is (are) not deinitely known. Usually all inlammatory processes are followed rapidly by anti-inlammatory defense response-excessive production of proinlammatory signals (mediators) and reactive oxygen and nitrogen species. The pro-inlammatory mediators (cytokines, chemokines, and eicosanoids) may stimulate proliferation of both untransformed and tumor cells [2]. The reactive oxygen and nitrogen species lead to oxidative stress and damage of macromolecules, especially DNA to increase the risk of genetic mutations and tumorigenesis [3].A continuously increasing number of microelements, vitamins, and mineral salts are reported to modulate the immune response and counter the inlamm...

Exploring the Immune-Boosting Functions of Vitamins and Minerals as Nutritional Food Bioactive Compounds: A Comprehensive Review

“…Compared with healthy individuals, the proportions of CD4 + lymphocytes were significantly higher in patients with vitamin B 12 deficiency, resulting in an abnormally high CD4 + /CD8 + ratio. In people with vitamin B 12 deficiency, NK cell activity is significantly reduced, and splenic NK activity is also reduced in rats fed a vitamin B 12 -deficient diet; however, no significant impacts on NK activity were observed in the axillary nodes or thymus [73,74].…”

“…The recommended amount of cobalamin for adults is 2.4 µg per day. Vitamin B 12 deficiency results in the downregulation of lymphocytes and affects the functionalities of NK cells, which are instrumental in abolishing cancer cells [73]. More precisely, patients with vitamin B 12 -deficient anemia have a smaller proportion of CD8 + T cells than the general population.…”

“…Intramuscular administration of vitamin B 12 (in the form of methylcobalamin) to patients who have recently been diagnosed with vitamin B 12 deficiency completely restores production of CD8 + T lymphocytes, returns the CD4 + /CD8 + ratio back to normal levels, and restores CD3CD16 + and CD3CD57 + counts (both of which have high NK cell activity) (Figure 1), which results in restored NK cell activity [73]. Conversely, vitamin B 12 deficiency or supplementation had no effects on immunoglobulin levels in the blood [73].…”

“…Intramuscular administration of vitamin B 12 (in the form of methylcobalamin) to patients who have recently been diagnosed with vitamin B 12 deficiency completely restores production of CD8 + T lymphocytes, returns the CD4 + /CD8 + ratio back to normal levels, and restores CD3CD16 + and CD3CD57 + counts (both of which have high NK cell activity) (Figure 1), which results in restored NK cell activity [73]. Conversely, vitamin B 12 deficiency or supplementation had no effects on immunoglobulin levels in the blood [73]. These findings suggest that CD8 + T cells can be upregulated, and the CD4 + /CD8 + ratio can be normalized by intramuscular cyanocobalamin injections in patients with pernicious anemia and low vitamin B 12 levels (three to ten times lower than the reference level) [75].…”

Potential Roles of Vitamins in the Management of COVID-19: A Comprehensive Review

“…Vitamin B12 acts as a coenzyme in metabolic reactions affecting fatty acids, DNA, and amino acid metabolism with potential binding affinity to the SARS-CoV-2 protease. 15,125 It is also responsible for inducing an imbalance in the cytokine and growth factor network in the central nervous system, enhancing the activity of NK cells as an essential factor in antiviral defense, 178,179 myelin synthesis, and modulating the gut microbiota. 116,120 Cobalamin deficiency is commonly observed in elderly individuals owing to decreased absorption secondary to their clinical situations and medicines, 180 and is associated with the reduced phagocytic and bacterial killing capacity of neutrophils, 58 low NK cell activity, low CD8+ T lymphocyte count, 160 impaired antibody response to the synthesis of specific Ig and pneumococcal polysaccharide vaccine due to the unavailability of vitamin B12 for swiftly proliferating lymphocytes, 158,181 increased oxidative stress, inflammation, and ROS.…”