What is the best frequency of vitamin b12 injection, if somebody doesn't have any deficiency but prefers to have shot?

If there is no: Measurable need for additional b 12 you are better off not taking it. If you are a vegetarian you need to keep an eye on your b 12 level via a lab test w/your doc. Meat is our primary source of b 12. In general, sublingual b 12 tablets that melt under the tongue is a good way to absorb b 12. Oral b 12 goes through the GI system and most of it is lost. Peace and good health.