I would like to know if taking vitamins, will they be compatible with the prescribed medicines I take every day like Synthroid, Glucophage, Celebrex, Protonix and Klonopin?

You need to read the pamphlets that come with the prescriptions, they usually have warnings if there's anything you can't take them with (ex/ yaz has a warning not to take too much potassium). If you don't have the pamphlets you can find a lot of them online usually. If you're still unsure after reading check with your dr.

Ask your pharmacist. They will know.

Yes, you can ask your pharmacist. However, are you talking about taking a regular multivitamin or are you talking about herbal vitamins? Herbs can interfere with meds, however, most multi-vitamins won't.