The TSA puts no restrictions on packing vitamins in pill form and powder supplements.
Healthy traveler packing tips: staying healthy while on vacation
Keeping up your vitamin regimen while you're on vacation can help you continue getting the nutrition you need, even if you fudge a bit on your diet. Pills, powders, liquids and softgels are all allowed to go with you on the plane in your carry-on luggage. You can also check them in with your other baggage. Here's what you need to know.
Dry vitamins in your carry-on
Go ahead and pack powdered supplements and vitamin pills in your carry-on case. You can keep them in their original bottles, put them in a daily pill minder or distribute them in any containers convenient for you. The Transportation Security Administration doesn't require you to declare them or pull them out of your bag unless asked.
Liquids and softgels in your carry-on
While you might think your fish-oil capsules or other softgels would need to go in your 3-1-1 bag, they don't. They can go in your carry-on with all your other vitamin pills. Liquids are a different matter, however. If your doctor has prescribed liquid vitamins through a pharmacy, you can bring more than the 3.4 ounces allowed by the TSA's 3-1-1 rule, in their labeled prescription bottles.
If your liquid vitamins don't have a prescription label on them, you'll need to follow the 3-1-1 rule when packing them. Make sure your vitamins are in a 3.4-ounce or smaller container and include the container in a single quart-sized clear plastic resealable bag along with any other liquids.
Nonprescription medicines in your carry-on
The TSA mandates that all passenger medications go through security screening. Separate your pills or liquid medications from your other items before you go through security. Liquid medication doesn't need to be inside a plastic bag, but you might want to store it in one to keep it from leaking inside your carry-on bag.
What to bring in your checked bag
You're free to pack as many vitamins, liquids, powders and other products as you wish in your checked baggage. There's a limit of 17 fluid ounces per container for medicinal and toiletry articles, with a maximum of 68 fluid ounces total for these products. Those rules don't apply when it comes to vitamins and supplements. So go ahead and pack that 5-pound canister of protein powder.