can you give yourself a b12 injection Vitamin Injections: Good or Bad? How To Give Yourself A
Description
(2) NNMT catalyzes the N-methylation of nicotinamide using SAM as a methyl donor, consuming both substrates in the process

Am J Respir Crit Care Med

This would be a significant deviation from how nutrient recommendations are normally formulated which is to base them on most peoples needs rather than outlier cases that require special treatment
However, these are typically associated with long-term mega-doses far exceeding whats in your weekly shot
[DOI] [PubMed] [Google Scholar] 33.Kannt A., Pfenninger A., Teichert L., et al