does a b12 injection hurt – When Is It Worth It and What Can You Feel After One Dose? Benefits of Vitamin B12 Shots

However, this is not usually done in practice

People with known cobalt allergy or Leber hereditary optic neuropathy should avoid cyanocobalamin because of reports of optic nerve damage

Monitoring Intake People with conditions that affect B12 absorption, such as pernicious anemia or gastrointestinal issues like Crohn's disease, should work with a healthcare provider to regularly monitor their B12 levels and adjust intake as needed

While many of the studies used animal models and have not been proven in humans yet, clinical trials are ongoing

Early manifestations include anxiety, headache, giddiness, inability to focus the eyes, and mydriasis