When flying to Europe in 2026, the most efficient way to pack vitamins is to keep them in their original, clearly labeled containers, though this is not a legal requirement for most Western countries. For solid forms (pills, capsules, gummies), there are no TSA or European customs quantity limits for personal use, and you are permitted to use daily pill organizers to save space. However, if you are carrying "large quantities" (more than a 90-day supply), customs officers may suspect you are importing them for resale, which can lead to questioning. For liquid vitamins, you must follow the "3-1-1" rule if they are in your carry-on (containers must be 3.4oz/100ml or less and fit in a quart bag); larger liquid bottles must go in checked luggage. For powdered vitamins (like protein or collagen) over 12oz (350ml), they must be placed in a separate bin for X-ray screening and may undergo additional testing. To avoid delays at European border control, having a digital photo of the original bottle's ingredient list on your phone is a helpful "pro-tip" in case an agent asks about the contents of your pill organizer.