In human and mouse intestinal cells grown in a lab, adding vitamin B12 increases the amount of ACE2 protein, the same receptor that SARS-CoV-2 uses to enter cells.
Claim Context
In human ileal epithelial cells cultured in vitro, vitamin B12 supplementation at 500 nM is associated with increased expression of the SARS-CoV-2 receptor ACE2, a finding conserved in murine ileal epithelial cells exposed to vitamin B12.
“Interestingly, VB12 increased the expression of the SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) in both murine and human iECs.”
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
Whether vitamin B12 status consistently correlates with ACE2 expression levels in human ileal tissue across diverse populations and health conditions.
A systematic review and meta-analysis of all human studies measuring ileal ACE2 mRNA or protein expression in relation to serum B12 levels, adjusting for age, sex, comorbidities, and medication use.
Whether oral vitamin B12 supplementation directly increases ACE2 expression in human ileal epithelial cells.
A double-blind RCT with 100 adults aged 25–50 with low-normal B12 (150–300 pg/mL), randomized to 1000 mcg oral B12 daily or placebo for 12 weeks, with ileal biopsies collected pre- and post-intervention for ACE2 mRNA and protein quantification.
Whether long-term vitamin B12 intake predicts sustained differences in ileal ACE2 expression over time.
A prospective cohort study of 400 adults with annual dietary B12 assessments and ileal biopsies collected at baseline and year 5 for ACE2 expression analysis, adjusting for confounders.
Whether individuals with low serum vitamin B12 have lower ileal ACE2 expression compared to those with normal levels.
A cross-sectional study comparing ileal ACE2 expression in 80 individuals with B12 deficiency (serum < 150 pg/mL) and 80 matched controls with normal levels (>400 pg/mL), all undergoing endoscopy for non-B12-related reasons.
Whether severe vitamin B12 deficiency is associated with reduced ileal ACE2 expression.
A case series of 5 patients with pernicious anemia and serum B12 < 100 pg/mL, with ileal biopsy ACE2 expression measured before and after B12 repletion.