I don’t know, I have played with it for 2-3 years now. There is some chemical in many commercial vitamins that does that to me. I CAN take liquid centrum with no issues. And I am playing with a liquid vitamin D3, but I can only take it every 3 days.
I also have severe IBS and Roemhelm Syndrome and have 3 different specialist trying to figure me out, lol. Right now a strict low FODMAP/low gas diet keeps me going. I have emergency meds for my heart issues, but I have been able to control it through diet so far.
A Dr. friend told me one can be allergic to a binder in a pill. A few years ago I picked up a different brand of Vit. C and it really pasted me - the sickest I’ve been in the last 10 years...