B12 Shots & B12 Injections: The Good, Bad and Alternative! B12 Shots at Home: How, Where & How Often to Inject Yourself AZ IV Medics If I took vitamin B12 injections and folic acid along with magnesium, a B complex, and carnitine, but there was no improvement and my condition actually worsened with increased anxiety, does this mean Vitamin B12 Deficiency Vitamin B12 deficiency happens when the body does not have enough vitamin B12. Vitamin B12 is important for making healthy red blood cells and keeping nerves