can b12 injections cause nausea Common & Rare Side Effects of Vitamin Why Do I Feel Worse

The best time to take vitamin B12 is whenever you can take it consistently

Patients with this condition cannot absorb B12 from food or oral supplements and require lifelong intramuscular replacement therapy

The Short-Term Timeline: Days 3 to 7 By the end of the first week, the initial surge settles into a steadier supply of B12, and this is often when the more noticeable day-to-day changes appear

IV administration might be chosen if you are already on IV fluids or need a very rapid correction of vitamin levels

Additionally, it occupies GIP receptors and mimics the action of the GIP hormone to enhance insulin release and promote fat breakdown