Most people can safely take vitamin B12, even at high doses. However, some people may be more likely to experience problems than others. Therefore, you should talk with your healthcare provider prior to taking the supplement if you have:
- Had a coronary stent
- Cobalamin or cobalt sensitivity
- Leber's disease
- Polycythemia vera
- Severe megaloblastic anemia
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Vitamin B12 Safety for more information, including any available warnings and precautions.)
What If I Take an Overdose?
With some vitamins, taking too much can quickly cause serious problems. However, this is not the case with vitamin B12. Overconsumption of this vitamin is unlikely to cause problems for most people.