Do you have full 23andMe results? If so, you can check to see if your GSTT1 or GSTM1 genes are missing. They can badly impair our ability to detox various substances, which does include pharmaceuticals and might include some supplements as well. Anyhow, it might help to narrow down why you aren't able to tolerate certain things.They have decided to do more testing which I am pleased about as I felt that the extent of my sensitivities was not being acknowledged and has now been shown since I have reacted badly to most of the supplements I was prescribed. B12 is a problem for me due to my MTHFR but I am managing to take small amounts.