How to Choose a Multivitamin
A multivitamin is not a substitute for a varied diet, but it can help fill gaps. Here is how to choose one sensibly.
Last reviewed: October 2026 · How we research
Disclosure: As an Amazon Associate I earn from qualifying purchases. This guide is general information, not medical advice. Talk to your doctor before starting any supplement.
Pick one made for your stage of life
Many brands offer versions for men, women, adults over 50, and prenatal use. The amounts of nutrients such as iron, calcium and folate differ between them for good reason. Iron needs in particular vary from person to person, so check with your doctor if you are unsure. Products for adults over 50 typically contain more calcium, vitamin D and B12 and less iron.
Read the Supplement Facts panel
- Percent Daily Value (%DV). Most nutrients land near 100% in a standard multivitamin. Extremely high percentages of some vitamins and minerals are not necessarily better.
- Serving size. Some products need two or more pills per day to reach the listed amounts. Compare cost per serving, not cost per bottle.
- Nutrient forms. Labels list forms like methylfolate or cyanocobalamin. You do not need to memorize them, but a clear, complete label is a good sign.
- Extras and herbal blends. The more extras in the formula, the more things to check against your medications.
Choose a format you will keep taking
- Tablets and capsules: Usually the most complete and affordable.
- Gummies: Easy to take but often contain added sugar and may leave out some minerals.
- Powders and liquids: Helpful if you have trouble swallowing pills.
Look for third-party testing
The supplement industry is lightly regulated, so a seal from USP, NSF or a similar independent lab is reassuring. It shows the contents were verified against the label. A seal is not a guarantee that a product is safe or effective, but it does mean an independent group tested it.
Before you start
- If you take warfarin, check with your doctor first, because vitamin K in some multivitamins can reduce how well the blood thinner works.
- Tell your doctor or pharmacist about all supplements you take, since some interact with medications.
- Take it with food if it upsets your stomach.
- Keep it away from heat and out of reach of children.
What Spain's government advises
Spain's Ministry of Social Rights, Consumer Affairs and the 2030 Agenda, passing on recommendations from the food safety agency AESAN, publishes a ten-point guide to using food supplements responsibly. Among its points: supplements should not replace a balanced diet, never take more than the dose on the label, tell your doctor which supplements you take, check the ingredients for allergies, be wary of products promising incredible effects, and remember that "a natural product is not the same as a safe product." It also recommends buying from authorized food retailers or pharmacies and being careful with unfamiliar sources on the Internet, which is a good reason to check who is actually selling a product on Amazon.
Sources and further reading
We read these pages in October 2026. They come from government health agencies in the United States and Spain and are not affiliated with this site. Where official advice differs between countries, we say so in the guide. Always follow the advice of your own doctor or pharmacist.
- NIH Office of Dietary Supplements: Multivitamin/mineral Supplements, consumer fact sheet (page dated February 2024)
- Spain, Ministry of Social Rights, Consumer Affairs and the 2030 Agenda (recommendations from AESAN): responsible use of food supplements (in Spanish; read October 2026)
- NIH Office of Dietary Supplements: Dietary Supplements, What You Need to Know (page dated January 2023)
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