Initial Posting: 5/28/2016    Last Update: 12/16/2019
Answer: Several supplements may be helpful when traveling (see the "What to Consider When Using" section in Product Reviews of specific supplements you may be planning on taking with you during a trip, for more detailed information about the best way to store your supplements.)
If you need a little help falling asleep, melatonin can be used and it may help you avoid jet lag after a long flight.
Keeping a few nutrition or meal replacement bars in your travel bag or purse may come in handy in case you experience unexpected transportation delays, or an outing takes longer than expected.
There is some evidence that ginger may be helpful if you are prone to motion sickness.
Taking certain probiotics several days before and during your trip may reduce the likelihood of developing traveler's diarrhea.
Probiotics may also offer some protection against colds and respiratory infections. If you do develop a cold, zinc lozenges may help to reduce the severity and/or duration of symptoms. (If you develop a cold while taking vitamin C, it may modestly reduce symptom severity and duration, but starting vitamin C supplementation after symptoms have already begun may not be helpful.)
Storage and Travel
Keep in mind when traveling that certain supplements, including some probiotics, fish oil and protein powders, are particularly sensitive to heat and moisture and should be packed and stored accordingly. Do not leave them in your car, and, when flying, keep them in your carry-on luggage rather than checking them with baggage since bags may sit out on the tarmac or in other environments which are not temperature controlled. (Remember, however, that liquid supplements in amounts greater than 3.4 ounces (100 mL), must be stored in checked luggage and cannot be kept in carry-on luggage.)
Although not required by the TSA, it may be helpful to keep your supplements in their original containers so they can be easily identified by security, especially if you are traveling abroad. In general, traveling in or out of the U.S. with supplements is permitted by the FDA as long as amounts are considered reasonable for personal use.
Radiation from airport security scanners is not likely to affect the quality or safety of vitamins and supplements. According to the FDA, "There are no known adverse effects from eating food, drinking beverages, using medicine, or applying cosmetics that have been irradiated by a cabinet x ray system used for security screening." A typical dose of radiation received by objects going through these systems is significantly lower than those used to irradiate food, and one study of medications such as acetaminophen found no change in drug content or quality after exposure to higher levels of radiation than used in typical scanners (Uehara, Drug Dev Ind Pharm 2015). Nevertheless, you may request that medications (and likely, supplements as well) be screened visually rather than by X-ray if you prefer.
If you have some favorite travel supplements or related tips, share them in the Comments section below!