Answer

Are supplements useful if you already eat a balanced diet?

Supplement Strategy strategy deficiency multivitamin

By Arun AgrahriLast reviewed 4 timecoded sources

Short answer

For people who already eat well, the evidence leans toward supplements adding little. Seven of the eight studies Precis has read point that way, though the tape is more split. In a 1-year trial in older adults, a cocoa flavanol supplement did not improve memory across the group. It helped only people with poorer diets or low flavanol intake.

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people who eat well and wonder if they need supplements at all.
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Based on what researchers say in public interviews on YouTube. Educational only, not medical advice. Ask a qualified clinician before changing a supplement, medication, treatment, or testing plan.

What the evidence says

positive partly neutral negative Each researcher and each study counts once per claim, however often they come up.

  1. Leaning for

    Supplements add little for people who already eat a balanced whole-food diet.

    19 sources: 10 positive, 6 partly, 3 negative.

    Researchers say

    2 positive, 5 partly, 2 negative

    Studies show

    8 positive, 1 partly, 1 negative

    8 papers we read · 2 cited on tape, not yet checked against the paper

    48 more not counted · see why
    We could not tell what position it takes on this claim. 24
    The study is not yet read in full. 11
    We could not confirm who is speaking. 8
    The study cited could not be identified. 4
    A host's remark inside an interview. 1
    Show the receipts from 19 sources

    1. Andrew Huberman, on Huberman Lab, at 35:30 Video · positive · Opinion

      “if you're eating well and doing the other foundational behaviors as well, you can get it way with a minimum of supplements.”

    2. Tim Spector, on The Diary Of A CEO, at 1:27:08 Video · positive · Opinion

      “if you have a good diet you won't need any supplements”

    3. COSMOS, multivitamin and mineral trial, cited on Rangan Chatterjee's channel, at 1:18:36 Study · positive

      “But it was because these people were falling behind. they had shortfalls in key nutrients.”

    4. Trial or observed group, Int J Sport Nutr, 1992, PMID 1299489 Study · positive

      In general, however, this study provided little evidence of any effect of supplementation to athletic performance for athletes consuming the dietary RDIs.

    5. Controlled trial, JAMA, 2012, PMID 23117775 Study · positive

      PHS II participants likely represent, on average, a well-nourished population who already have adequate or optimum intake levels of nutrients, for which supplementation may offer no additional benefit.

    6. Controlled trial, Ann Intern Med, 2013, PMID 24490265 Study · positive

      A limitation of this study is that our population of male physician participants may have been too well nourished to observe benefits of supplementation.

    7. Other primary study, Ann Intern Med, 2019, PMID 30959527 Study · positive

      Adequate nutrient intake (≥ Estimated Average Requirement or Adequate Intake) of vitamin A, vitamin K, magnesium, and zinc was associated with reduced all-cause or CVD mortality, but the associations were confined to nutrient intake from foods not supplements.

    8. Controlled trial, Am J Clin Nutr, 2022, PMID 35294969 Study · positive

      Baseline nutritional status is another important consideration, as COSMOS participants may already have adequate or optimum nutrient intake for which MVM supplementation may offer limited benefits ( 65 ), whereas nutritionally vulnerable populations may improve nutritional status with broad-based MVMs ( 58 , 66 ).

    9. Controlled trial, Proc Natl Acad Sci U S A, 2023, PMID 37252983 Study · positive

      While the prespecified primary end point testing for an intervention-related improvement in memory in all participants after 1 y was not statistically significant, the flavanol intervention restored memory among participants in lower tertiles of habitual diet quality or habitual flavanol consumption.

    10. Other primary study, JAMA Netw Open, 2024, PMID 38922615 Study · positive

      In stratified analyses, we found no evidence of effect modification by race and ethnicity, education, or diet quality.

    11. Elizabeth Boham, on The Dr. Hyman Show, at 12:14 Video · partly · Opinion

      “many times people have either because of genetic reasons or digestive reasons and they're not absorbing optimally”

    12. Rich Roll, on FoundMyFitness, at 22:05 Video · partly · Opinion

      “And I found that for the most part, I don't need most of those things that I thought that”

    13. Dr. Marie-Pierre St-Onge, on Huberman Lab, at 1:51:45 Video · partly · Opinion

      “some people who may need to supplement their diets, but I think people should strive to to get their nutrients from uh from whole foods”

    14. Dr. Layne Norton, on FoundMyFitness, at 3:24:45 Video · partly · Opinion

      “always tell people fruits and vegetables Whole Foods are better if you need a fiber supplement okay a fiber supplement”

    15. Rupy Aujla, on Rangan Chatterjee's channel, at 1:41:48 Video · partly · Opinion

      “in that context I didn't need a protein supplement to get to the level that I require”

    16. Controlled trial, Stroke, 2009, PMID 19118243 Study · partly

      In conclusion, BVAIT indicates that B-vitamin supplementation significantly reduces progression of early stage subclinical atherosclerosis in well-nourished healthy B-vitamin “replete” individuals at low-risk for CVD with a fasting tHcy≥9.1 μmol/L.

    17. Mark Hyman, on The Dr. Hyman Show, at 29:46 Video · negative · Opinion

      “if that's you you don't need supplements but everybody else you need supplements”

    18. Michael Murray, on The Dr. Hyman Show, at 22:58 Video · negative · Opinion

      “the nutrients our body needs but also the phytochemicals from diet alone and the simple answer is no”

    19. COSMOS, three cognition trials in adults 65+, cited on Huberman Lab, at 2:47:23 Study · negative

      “and after a year of taking this multivitamin it globally reduced brain aging by about 2.1 years”

Where the sources disagree

Leaning for

Supplements add little for people who already eat a balanced whole-food diet.

Supports it 10 sources

Researchers

Studies

Partly 6 sources

Researchers

Studies

Against it 3 sources

Researchers

Studies

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Detailed Answer

Nineteen sources count toward this claim: 11 on tape and eight studies Precis has read. The studies lean toward supplements adding little. The tape splits three ways.

What the studies found

Most are trials in groups their authors call well nourished. In the Physicians' Health Study II, a multivitamin did not help the heart or memory of male doctors. Its authors say the doctors were likely well nourished already, so the pill had little to add.

The COSMOS multivitamin trial's authors say the same of their group, and that people with poorer nutrition may gain more.

A US cohort study looked at vitamin A, vitamin K, magnesium and zinc. Getting enough of them went with fewer deaths, but only when they came from food, not supplements. A study of three US cohorts found that diet quality did not change how multivitamin use related to death.

Where a supplement helped some people

Two trials found a gain in only part of the group. In a COSMOS trial of cocoa flavanols, memory improved only in older adults with poorer diets or low flavanol intake. A trial gave high-dose B vitamins to healthy, well-nourished adults.

It slowed early artery hardening in those with a fasting homocysteine (an amino acid in the blood) of 9.1 µmol/L or higher. That trial counts as partly for the claim.

Where the tape splits

Three sources say a good diet leaves little to add. Tim Spector, a guest on The Diary of a CEO, says "if you have a good diet you won't need any supplements," but adds that most people don't have one. Andrew Huberman, at a live Q&A, says you can get away with a minimum if you eat well.

Jenna Macciochi, a guest on Rangan Chatterjee's show, credits a COSMOS gain to nutrient shortfalls.

Three say most people still need them. Mark Hyman, on his own show, says you can skip them only if you hunt and gather your food and sleep nine hours a night. Michael Murray, a guest on Hyman's show, says the food supply has changed too much.

A COSMOS retelling on Huberman's show with Rhonda Patrick describes three trials in adults 65 and older, where a year on a daily multivitamin slowed brain aging by about 2.1 years.

Five say it depends on the person, such as someone who absorbs nutrients poorly.

Studies not counted yet

Eleven more, read only from the abstract, do not count yet. Ten others wait for a third reader, because the first two split. They hold the two results that cut most against the claim. One is a small drop in cancer in the Physicians' Health Study II. The other is a small memory gain in a COSMOS trial that did not depend on diet quality.

What no study has tested

No trial Precis has read enrolled people because they eat a balanced diet. The COSMOS trials, as described on tape, enrolled adults 65 and older, and the tape does not say how well they ate.

Related Questions

Is a multivitamin worth taking if you already eat well?
The studies Precis has read lean toward no. In two multivitamin trials, the authors say their groups were likely well nourished, so the pill may have had little to add. On tape, one reading of three COSMOS trials in adults 65 and older found about 2.1 years less brain aging after a year on a daily multivitamin.
Which nutrients are hardest to get from food alone?
On tape, creatine and vitamin D. Huberman says the meat needed for a creatine effect is far too much to eat, so he takes five grams a day. Attia says that without a supplement his vitamin D is lucky to be above 40, so he takes 5,000 IU a day. Neither is counted toward this claim.
Who might need supplements even on a good diet?
In the studies Precis has read, gains showed up in people with poorer diets or low intake of the nutrient. On tape, Elizabeth Boham points to people who absorb poorly for genetic or digestive reasons, and St-Onge allows that some people may need to supplement.

More Questions About Supplement Strategy

How many supplements is too many? Do you need B12 supplements? How much vitamin D should you take per day? How much omega-3 per day should you take? How do you know if a supplement is good quality?

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