Your first step before traveling is to make sure you need no immunizations where you are going. That's easy; you can even set up a pretravel consultation (available at CVS MinuteClinic locations) for a practitioner to assess your travel health needs and advise on any immunizations or health considerations based on where you're headed.
But for those daily vitamins you try to take no matter where you go, instead of packing your vitamins and supplements in Ziploc bags or pill boxes, you can subscribe to Vitamin Packs, a subscription vitamin and supplement company whose customized and individually packed vitamin packs can help you maintain wellness on the road. Just throw a pack in your carry-on for each day you are traveling and you're set. If you are on any medication, see if you can transfer prescriptions from one pharmacy to another without needing to call your doctor for a new prescription.