how soon do b12 injections work Long Does It Take For To Work? How Quickly Do You Feel

Long-term untreated vegan diet where deficiency has progressed beyond what oral replacement can comfortably catch up

Some health problems can make it hard for the body to take in vitamin B12

5 and Supplementary Fig

Sublingual tablets and nasal sprays bypass some of the digestive steps, which may be helpful if you have absorption challenges or prefer not to swallow pills. Vitamin B12 injections deliver the vitamin directly into your bloodstream, bypassing the digestive tract and providing faster, more reliable absorption

In extreme cases, people with pernicious anemia or a related condition known as vitamin B12 deficiency myelopathy can develop nerve damage related to vitamin B12 deficiency