can you inject liquid b12 Sublingual vs. B12 Injections: Which Option Is Right for You? – WhyNotNatural B12 Shots vs. IV Infusions:
Description
Surgeries to remove parts (or all) of the stomach or small intestine

The body converts it to methylcobalamin and adenosylcobalamin so that it can be used

Signs You Might Be Vitamin B12 Deficient It's important for everyone, regardless of dietary choices, to be aware of potential B12 deficiency symptoms and seek medical advice if they arise

If the goal is scale weight, this is not the right tool
