BACE1 and vitamin B deficiency: Because we previously demonstrated20, 23 that BACE1 mRNA was inversely regulated by B vitamin deficiency and SAM supplementation in respect to what we observed for miR‐29a (i.e., BACE1 is upregulated in B vitamin deficiency and downregulated by SAM), and considering it is targeted by this miRNA, we performed gain‐ and loss‐of‐function assays to mechanistically link these RNA expression results.