what size syringe for b12 injections gauge and length needle should be used an intramuscular vitamin injection in an adult? B12 Injection Kit: Syringes &
Description
What does a B12 deficiency look like

You can change your mind at any time and increase your dose with your doctors approval, as long as its been at least 4 weeks on your current dose but you cannot take more than 2.4mg a week
To start, you should book a consultation with a doctor

Vitamin B12 Deficiency Since your body reserves some vitamin B12, a deficit may not manifest for several years