Can b12 shot be a boost if level low?

A good maybe: I often hear that from patients--feeling more energetic from a B12 injection..Even when their level is normal..Even high-normal. So, if you have low level to start with and you need it, i don't really see the downside..So give it a shot...You may feel better. I assume you have a work-up by your doc to make sure no anemia or low thyroid etc... Good luck.

Absolutely: If your vit B12 level is low you should receive vit B12 replacement- through injection in the muscle commonly. Usually it is given periodically- once a week for a month to start with then monthly basis. Talk to your doctor and start the treatment. If your vit B12 is low- also important to know what the cause - this is something your doctor can help you as well.

Is it worth a shot?: Some people report being mentally sharper or more energetic if they take vitamin b12. Some physicians treating many seniors consider giving monthly B12 injections if the level is low. I will share this question with specialists who can add studies or data comments.

Sure: B12 deficiency can have subtle symptoms, vague symptoms, fatigue, depression, as well as more serious neurol signs and symptoms (poor balance, hearing loss); can cause anemia (if also folate (folic acid) deficient). Not rare in elderly. Can usually store 5 years worth, so vegans don't commonly get it. Risk if stomach/pancreas, ileum diseases, maybe from acid reducers too. Methyl malonic acid test confirms.