can you inject b12 into a vein Injections at Home - Safety Guide for Self-Administration B12 Shots for Total Well-being

doi:10.1128/AEM.02173-12

After a brief consultation, the injection is administered comfortably into the upper arm or gluteal muscle

But it could be helpful to screen people for B12 deficiency in advance and give them B12 supplements to delay or prevent the onset of depression

The key point: B12 treatment reliably helps people who are actually low in B12

The objective is to support higher quality study planning, clearer reporting, and improved reproducibility for laboratories working in NNMT biology, one carbon biochemistry, NAD+ pathway studies, and systems level metabolism

The most common deficiencies involved vitamin B12, vitamin D, and folate