i've been told, if you are vegan and you eat something that is non-vegan it can make you ill. the person that told me this is not vegan, but has a friend that is. apparently his friend was at work and it was someones birthday. his boss told him that the birthday cake was a vegan cake (which it wasn't). so, his friend ate a piece. when i asked the person if he got sick, he couldn't recall. if anyone has had any experience or knows the answer, please let me know.