Medicare and Medicaid, Vitamins
What Medicare covers depends on your Part D plan, which is the part that covers prescription drugs. That said, I'm pretty sure none of the Part D plans cover over the counter things like vitamins. They might cover prescription vitamins, like the B12 nasal spray or shots.
As far as I know, Medicaid doesn't cover OTC stuff, either. Medicaid rules vary from state to state, though. In Ohio, where I am, Medicaid won't cover OTC stuff. However, I have a Medicaid spend down, and I can use some expenses not covered by Medicaid to meet my spend down. For instance, if I have a letter from my doctor saying I need to take D3 due to a vitamin D deficiency, and I buy that D3 over the counter, I could turn in that receipt towards my spend down.
Please note: I AM NOT A DOCTOR. If you want medical advice, talk to your doctor. Whatever I post, there is probably some surgeon or other health care provider somewhere that disagrees with me. If you want to know what your surgeon thinks, then ask him or her. Check out my blog.