Is There a Carcinogenic Risk Attached to Vitamin B₁₂ Deficient Diets and What Should We Do About It? Reviewing the Facts

Abstract

The number of individuals partaking in veganism has increased sharply in the last decade. Therefore, it is critical to look at the implications of vegan diets for public health. Although there are multiple health benefits of a vegan diet, studies have also linked the diet with deficiencies in various micronutrients. This study focuses on vitamin B12, because of its critical role in DNA synthesis and methylation. In light of these connections, a critical review of recent scientific literature is conducted to understand the effects of a B12 deficient diet on the genome and epigenome, and whether it can give rise to cancer. It is observed that a B12 deficiency leads to increased uracil misincorporation, leading to impaired DNA synthesis and genomic instability. The deficiency also leads to global hypomethylation of DNA, a hallmark of early carcinogenesis. The findings of this study highlight the need for increased awareness among vegans to ensure adequate B12 intake through supplementation or consumption of fortified products as a preventative measure. Additionally, the biofortification of staple crops and an improved version of fermented products with increased B12 content can be developed when inadequate intake seems otherwise inevitable.

Homocystein, Vitamin B12 and Folic Acid as Screening Biomarkers in Early Diagnosis and Gastric Cancer Monitoring

“…Miranti in 2017 [ 18 ] also identified an increased risk of developing cancer up to 5.8 times more than the control when patients had a low vitamin B12 concentration, presuming that the low intake of this vitamin would be due to an initial gastritis, for example, since, for satisfactory absorption, an intact gastric mucosa is required to produce acid and intrinsic factor. Corroborating our finding, Loedin and Speijer highlight that B12 deficiency enhances the incorrect incorporation of uracil into the genetic code, leading to impaired DNA synthesis and increasing genomic instability [ 19 ]. Furthermore, it is known that low levels of Vitamin B12 are also associated with global DNA hypomethylation, a known hallmark of early carcinogenesis [ 20 ].…”

The Impact of a Vegan Diet on Many Aspects of Health: The Overlooked Side of Veganism

“…Global hypomethylation of DNA is a characteristic of early carcinogenesis. Thus, if not adequately replaced, VD may inadvertently lead to cancers [ 20 ]. Wu et al found that blood B12 levels were substantially lower in menopausal and postmenopausal breast cancer patients, and patients with the lowest B12 levels had an elevated risk of breast cancer [ 21 ].…”

Histone Acyl Code in Precision Oncology: Mechanistic Insights from Dietary and Metabolic Factors

“…Deficiencies in essential nutrients like folate [134,135], vitamin B12 [136], and iron [137], which function as critical cellular substrates and cofactors, can impair the function of enzymes involved in histone acylation, leading to abnormal histone modifications and potentially promoting oncogenesis. Altered metabolite levels and imbalanced nutrient utilization can also affect the activity of HATs and HDACs, which regulate histone acylation.…”