Veggie Blog

Vitamin supplements are a big business, and shelves in stores and websites are full of choices. The old version of this post claimed that liquids are the best form, that tablets need special binders to dissolve, and that vitamins are “great for athletes” looking for energy. None of that is backed by good evidence, so I have replaced it with guidance from the National Institutes of Health. Here is how to choose a supplement sensibly, if you need one at all.

Do you need a supplement?

Maybe not. The NIH Office of Dietary Supplements (ODS) says that some supplements can help you get adequate amounts of essential nutrients if you do not eat a nutritious variety of foods, but that supplements cannot take the place of the variety of foods that are important to a healthy eating routine. Some have clear roles: calcium and vitamin D help keep bones strong, and folic acid decreases the risk of certain birth defects. Many other supplements need more study to determine whether they have value. Our guides to vitamins and your health and vitamin deficiency explain who is most at risk of falling short.

What forms do supplements come in?

According to ODS, supplements come in a variety of forms, including tablets, capsules, gummies and powders, as well as drinks and energy bars. There is no single best form. The main difference is convenience and taste: if you cannot swallow pills, a liquid or a chewable may suit you better. The old post claimed that liquids are best and that tablets often pass through the body undissolved, but I could not find authoritative support for either claim. Our post on liquid, chewable and tablet vitamins looks at this question in more detail.

How do you read the label?

Products sold as dietary supplements carry a Supplement Facts label that lists the active ingredients, the amount per serving and other ingredients such as fillers, binders and flavorings. Check the dose against the recommended amounts, and add up everything you take, because manufacturers may add vitamins and minerals to foods such as breakfast cereals and beverages, so you may get more than you think. ODS notes that more might not be better, and that taking more than you need costs more and might raise your risk of side effects. For example, too much vitamin A can cause headaches and liver damage.

Are supplements checked by the FDA?

Not in the way that medicines are. ODS says that dietary supplements are not medicines and are not intended to treat, diagnose, mitigate, prevent or cure diseases, and that the FDA does not determine whether supplements are effective before they are marketed. The FDA has set Good Manufacturing Practices that companies must follow, and several independent organizations, including ConsumerLab.com, NSF International and U.S. Pharmacopeia, offer quality testing and seals. ODS adds that these seals indicate a product was properly manufactured, contains the ingredients listed on the label and does not contain harmful levels of contaminants, but that they do not guarantee that a product is safe or effective. Read the full ODS guide, Dietary Supplements: What You Need To Know.

What are the risks?

ODS says you are most likely to have side effects if you take high doses, take supplements instead of prescribed medicines, or take many supplements at once. Some supplements can increase the risk of bleeding or change your response to anesthesia if taken before surgery, and some interact with medicines. Examples include vitamin K, which can reduce the effect of the blood thinner warfarin, and St. John’s wort, which can reduce the effectiveness of many medicines. Be careful about giving supplements to children, and in pregnancy or breastfeeding, unless a health care provider recommends them.

What is the bottom line?

Tell your health care providers, including your pharmacist, about every supplement you take, and ask which ones, if any, might be valuable for you. Keep a list. Build your diet around vegetables, fruit, whole grains and protein foods first. Read about how and when to take vitamin supplements for practical timing tips, and about whether vegetarians need supplements if you follow a plant-based diet.