can b12 injection cause dizziness Why do I feel worse after a injection? Feeling worse after B12 Injection:

This makes oral supplements less effective for individuals with: Pernicious Anemia: An autoimmune condition where the body can't produce intrinsic factor

Kimura, et al

Although a vitamin B12 overdose is rare, research suggests that some groups of people are at a greater risk of adverse effects from taking an excessive amount of the nutrient

Her other recommendation was running two packs together but if the bleeding starts after two weeks I dont see the point

supporting greater weights at weaning, better immunity against parasites and potentially fewer drenches as well as a reduced need for regular trace element supplementation