Do I Need a Supplement? A Food-First Way to Think About It
A food-first way to decide whether a supplement makes sense for you: what government dietary advice says, when guidance points to a supplement, and what research says about multivitamins.
Content last updated . This page has not been medically reviewed.
The short answer
There is no single answer that fits everyone. Government nutrition advice in both the US and the UK starts with food: the UK's NHS says most people should get all the nutrients they need from a varied and balanced diet, although some people may need to take extra supplements. [1] The US Dietary Guidelines say nutritional needs should be met primarily from foods and beverages, and that fortified foods and supplements are useful in some cases when needs cannot otherwise be met, for example in pregnancy. [2] This page helps you ask the question well. It does not give a routine to follow, and it cannot tell you what you personally need.When official advice points to a supplement
These are examples from the sources we read. Each applies to a specific group in a specific country.| Situation | What the source says | Where |
|---|---|---|
| Autumn and winter, little sun | Everyone should consider a daily vitamin D supplement of 10 micrograms during autumn and winter; some groups are advised to take it all year. [3] | UK (NHS) |
| Planning a pregnancy or capable of pregnancy | The Dietary Guidelines report that the US Preventive Services Task Force recommends all women planning or capable of pregnancy take a daily supplement containing 400 to 800 mcg of folic acid, starting at least 1 month before conception. [2] | US (Dietary Guidelines) |
| Babies | Provide infants with supplemental vitamin D beginning soon after birth. [2] | US (Dietary Guidelines) |
| Vegan diet | B12 deficiency from diet is uncommon but can happen on a vegan diet without B12 supplements or fortified foods. [4] | UK (NHS) |
| Older adults | Some individuals may require vitamin B12 supplements; the guidelines encourage talking with a health care provider about what, if any, supplementation is appropriate. [2] | US (Dietary Guidelines) |
Note what these have in common: a defined group, a reason, and a specific nutrient. They are not advice to take "something for general health."
What research says about general-purpose multivitamins
- Longevity and disease prevention. NCCIH (part of the US National Institutes of Health) says most research shows multivitamins do not result in living longer, slowing cognitive decline, or lowering the chance of cancer, heart disease or diabetes. It also says taking a multivitamin is unlikely to pose any health risks. [5]
- Heart disease and cancer prevention in healthy adults. The US Preventive Services Task Force (2022) concluded the evidence is insufficient to judge the balance of benefits and harms of multivitamins for preventing cardiovascular disease or cancer. It recommended against beta-carotene or vitamin E supplements for that purpose. This applied to community-dwelling, nonpregnant adults. [6]
Evidence label: insufficient evidence or no clear benefit for prevention in well-nourished adults; established role where a deficiency or a defined need exists.
Questions worth asking first
- What am I hoping to change, and is there evidence for that supplement and that outcome? See Supplement research and evidence.
- Can food or a fortified food cover it? See Food-first nutrition.
- Is there a real shortfall? Symptoms alone cannot tell you. See Deficiency testing and its limits.
- How much is in the product compared with reference intakes? See RDA, AI, DV and UL.
- Is it safe alongside my medicines and conditions? See medication interactions and talking with a health professional.
Safety note
Supplements can interact with medicines, affect surgery and may not have been tested in pregnancy or in children. [5] More is not automatically better. Tell your health care provider about everything you take. Safety pages are gathered in Supplement safety resources.Frequently asked questions
Do I need a multivitamin?
Not automatically. Most research found no benefit for living longer or preventing common diseases, and a US task force found the evidence insufficient for heart disease and cancer prevention. [5][6] Specific groups may be advised to take specific nutrients. [2][3]
Can a supplement replace a healthy diet?
No. US dietary advice says needs should be met primarily from foods and beverages, and the NHS says most people can get what they need from a varied, balanced diet. [2][1]
Is a multivitamin harmless?
NCCIH says a multivitamin is unlikely to pose health risks, but supplements in general may interact with medicines or pose risks with certain conditions or surgery. [5]
References
- NHS (UK). Vitamins and minerals. Page last reviewed 3 August 2020. Read 2026-10-22.
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans, 2020-2025. Read 2026-10-22.
- NHS (UK). Vitamin D. Read 2026-10-22.
- NHS (UK). Vitamin B12 or folate deficiency anaemia. Read 2026-10-22.
- National Center for Complementary and Integrative Health (NIH). Using Dietary Supplements Wisely. Read 2026-10-22.
- US Preventive Services Task Force. Vitamin, Mineral, and Multivitamin Supplementation to Prevent Cardiovascular Disease and Cancer: Recommendation Statement. JAMA 2022;327(23):2326-2333. PMID 35727271. Read 2026-10-22.