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

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.

Saliva "Treat-and-Heat" Triplex Reverse Transcription Loop-Mediated Isothermal Amplification Assay for SARS-CoV-2.

The demand for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) molecular diagnostics that are faster, cheaper, and simpler to run than nasopharyngeal-based reverse transcription quantitative PCR (RT-qPCR) tests remains unmet in many parts of the world. In the Philippines, geographical and economic access to quality diagnostic testing remains out of reach for many communities. We describe the preclinical development of a fluorescence-based reverse transcription loop-mediated isothermal amplification test that uses drooled saliva as the biospecimen. Six treat-and-heat ("direct") procedures that inactivate the virus and release the target RNA were compared. Using duplexed As1e and E1 primers, protocols derived from Ben-Assa et al. (2020) using proteinase K or from Rabe and Cepko (2020) using TCEP (Tris(2-carboxyethyl)phosphine hydrochloride)/EDTA provided reliable RNA amplification. The TCEP/EDTA-based method in particular showed improvement in robustness in duplex vs. singleplex format. Inclusion of human ß-actin primers provided a triplex test with an internal amplification control that could be distinguished from SARS-CoV-2 amplicons based on melt curve analysis. After including the dUTP/uracil-DNA glycosylase system and implementing laboratory procedures to avoid cross-contamination, false positive amplification was acceptably rare. The duplex or triplex tests are predicted to reliably detect patient salivary viral loads >100 copies/µL and to yield equivocal results between 10 and 100 copies/µL. These viral loads, corresponding to RT-qPCR C t ∼29-32, are expected to identify the majority of infected and, particularly, of infectious patients. If clinically validated, the test would provide additional testing capacity requiring only a fraction of the time, cost, and infrastructure of the current nasopharyngeal swab-based RT-qPCR test, thereby improving access to testing for more Filipinos.