Vitamins are non-prescription. They’re also totally fine. You can rattle your fistful of gummy vitamins at security all you like. They won’t bat an eye.
But here’s a funny thing: some supplements, like melatonin or certain herbal remedies, aren’t technically “medication” in the UK. They’re food supplements. Still fine to carry.
Just don’t try to bring back mysterious powders from abroad. That’s a different story, mate. Different article.
Carry Medicines in Flight: Traveling by Plane with Medication? Know
What about medical evidence?
For non-prescription stuff? Usually not needed. But if you’re carrying a massive bottle of ibuprofen like it’s your life source, bring a note from your doctor. It covers your backside.
Also, if you have a condition that requires regular pain relief, keep a prescription or a letter handy. Security loves paperwork. They really do.