What are the side effects of too much vitamin B12?

Vitamin B12 is fairly non-toxic, but some rare side effects include:

* Diarrhea * Blood clots in the legs * Feeling of swelling around the entire body * Hives or rash* * Itching* * Swelling of lips, mouth of throat* * Difficulty breathing* * Signs of an allergic reaction

You may also experience toxic effects from the inactive ingredients in the supplement.