can b12 injection be given in arm Shots at Home: How, Where & How Often to Inject Yourself Vitamin C and B12 Injection
Description
2013;3(1 to 2):7 to 15

In Warren MJ, Smith (eds.)
3f), and its relative abundance was lowest in WD control mice compared to all other groups

If you are not deficient and are taking it as a supportive measure, you might not feel any dramatic change, and thats okay
