I had taken the chewables in orange flavour for half a year and did not experience any negative effects. One day I decided to try the grape flavoured chewables and it gave me an anaphylaxic reaction. I ended up in the hospital and still didn;t know what hit me. Later I realized that the grape version had contained a "natural' colorant called Carmine Purple (ground up small beetles, just google it), which I now know I am severely allergic to.

I'd rather Jamieson had not used these colorants and just kept it natural.