Dietary Supplement: How to Choose, Use, and Stay Safe

Roughly half of adults take at least one dietary supplement. That makes sense—who doesn’t want an easy way to fill gaps in their diet? But supplements aren’t a replacement for food or medical care. Use this guide to pick the right products, avoid common risks, and get the benefits without the headaches.

How to choose supplements

Start by asking why you need a supplement. Pregnant people need folic acid to lower birth defect risks. Older adults often need vitamin B12 or vitamin D. Vegans may require B12 and iron. If you don’t have a clear reason, a basic multivitamin is usually safer than high-dose single nutrients.

Check the label. Look for the active ingredient, serving size, percent daily value, and any added fillers. Prefer brands that list third-party testing from groups like USP, NSF, or ConsumerLab—those seals mean the product contains what the label claims and isn’t contaminated.

Avoid products with wild claims: rapid weight loss, miracle cures, or guaranteed performance boosts. If it sounds too good to be true, it usually is.

Safety, dosing, and interactions

More isn’t always better. High doses of some vitamins (A, D, E, and K) and minerals can cause harm. Stick to the recommended dose on the label or follow a clinician’s advice. Keep track of all medicines and supplements you take—many supplements interact with prescription drugs.

Examples: St. John’s wort lowers effectiveness of some antidepressants and birth control. High-dose vitamin E can increase bleeding risk if you take blood thinners. Fish oil may affect blood clotting at high doses. Tell your doctor or pharmacist about supplements before surgery or when starting new prescriptions.

Watch for allergic reactions or unusual side effects. If you feel worse after starting a supplement, stop it and check with a health professional. Pregnant or breastfeeding people, children, and people with chronic conditions should always consult a clinician first.

Buying tips and storage

Buy from reputable retailers or verified online pharmacies. Avoid products with missing contact info, fake reviews, or claims that they can replace prescriptions. Store supplements in a cool, dry place and check expiration dates—ingredients can lose potency or break down over time.

Keep a simple list of what you take, why you take it, and the dose. Share that list with your healthcare provider during visits. That small habit prevents dangerous interactions and helps your clinician give better advice.

Quick checklist

- Know why you’re taking it. - Read the label and serving size. - Choose third-party tested brands. - Avoid mega-doses unless prescribed. - Tell your clinician about supplements.

Supplements can help when used smartly. Choose products for clear needs, check for testing seals, and keep your healthcare team in the loop. That’s the simplest way to get benefits and avoid trouble.