The short answer
For most healthy adults who eat adequately, no. In large trials and cohorts of well fed adults, all-cause mortality, cardiovascular disease and total cancer did not differ between multivitamin users and non-users or placebo groups12. On memory tests in adults aged 60 and over, the gaps between multivitamin and placebo groups were a few hundredths of a standard deviation, and a 2026 review found no benefit across multiple cognitive domains58. NOTFORTOMORROW does not sell a multivitamin, and this article explains why.
What did the large multivitamin trials actually test?
The trials tested disease outcomes in specific populations, not general wellness. COSMOS randomized older US adults without major cardiovascular disease or recent cancer to a daily multivitamin or placebo for a median of 3.6 years, with total invasive cancer as the primary outcome2. The Linxian trial randomized Chinese adults aged 40 to 69 with esophageal squamous dysplasia, a population with a high prevalence of undernutrition, and followed them for 29 years3. Cohort data from three large US cohorts tracked self-reported multivitamin use for up to 27 years1.
These are different questions in different people. COSMOS measured cancer and cardiovascular events in older, largely well nourished Americans. Linxian asked whether a multivitamin changes mortality in a population where nutrient intake was genuinely low. Neither asked whether a multivitamin corrects a diagnosed deficiency, because participants with known deficiencies were not the target group.
What did the trials measure for death, heart disease and cancer?
No, not in well fed adults. In COSMOS, total invasive cancer did not differ significantly between groups: HR 0.97 (95% CI 0.86 to 1.09) over a median 3.6 years2. Composite cardiovascular disease was HR 0.98 (95% CI 0.86 to 1.12) and all-cause mortality HR 0.93 (95% CI 0.81 to 1.08)2. In three large US cohorts followed for up to 27 years, daily multivitamin use was not associated with lower mortality, with a multivariable-adjusted HR of 1.04 (95% CI 1.02 to 1.07) in the first half of follow-up1.
What did the trials measure on memory and thinking?
In COSMOS-Web, a 3-year trial in 3,562 older adults, there were no significant effects on secondary outcomes such as novel object recognition and executive function6. In COSMOS-Mind, new cases of mild cognitive impairment and dementia did not differ between the groups over 3 years, although the study had low statistical power7. A 2026 rapid review of meta-analyses, which pooled randomized and observational evidence, found no benefit across multiple cognitive domains8.
Who were these trials about, and who was left out?
The headline trials studied older, mostly well fed adults without major chronic disease. COSMOS enrolled adults aged 60 or 65 and over, free of major cardiovascular disease and recent cancer2. The cohort data covered US adults with a median age of 61.5 years, 55.4% male, without a history of cancer or other chronic diseases at baseline1. People with documented deficiencies, pregnant women, younger adults and populations with poor diets were largely not who these studies measured.
Linxian shows why that matters. In Linxian, where undernutrition was common, supplementation for 6 years did not change total mortality over 29 years of follow-up (HR 0.96; 95% CI 0.89 to 1.03) in the whole group3. Some subgroups, older men and younger men, showed different death rates from heart disease, stroke and esophageal cancer, but these were exploratory analyses3. These are exploratory subgroup findings, not a prescription, but they show that baseline nutrient status changes what a trial can find.
Why can a trial find nothing when a nutrient still matters?
Because a trial can only find an effect where a shortfall exists. If almost every participant already has adequate intake of every vitamin and mineral in the pill, there is nothing to correct, so the expected effect is zero and that is what the trials measured. This is why no effect on mortality in well fed American adults says nothing about a person with a documented vitamin D or B12 shortfall. A blanket multivitamin and a targeted nutrient are also different tools, which the next section makes concrete. If you suspect a shortfall, blood testing before supplementing, as we explain in our article on blood markers, is the more rational route than a broad pill.
How does a multivitamin differ from a single targeted nutrient?
A multivitamin spreads small doses across many nutrients; a targeted supplement delivers a meaningful dose of one nutrient chosen for a reason. That difference matters for both effect and safety.
| Aspect | Daily multivitamin | Targeted single nutrient |
|---|---|---|
| Dose per nutrient | Small amounts of many vitamins and minerals at once | One nutrient at a chosen dose, for example 5000 IU vitamin D3 per 0.25 ml serving taken every 3 days, or 500 µg B12 per capsule |
| Who it suits | People with a broadly restricted diet who cannot change it | Anyone with a tested or likely shortfall in that specific nutrient |
| What it cannot do | Replace a varied diet or supply a large dose of one nutrient | Anything beyond its one nutrient |
| Evidence base | Large trials in well fed adults: no difference in mortality or cardiovascular disease12; small memory test differences in older adults5 | Nutrient-specific trials and blood-marker guided use |
For context on our own range: our vitamin D3 + K2 drops deliver 5000 IU vitamin D3 (125 µg) with vitamin K2 as MK-7 per 0.25 ml serving, taken every 3 days, with the authorised claim that vitamin D contributes to the normal function of the immune system and to the maintenance of normal bones. Our bioactive vitamin B complex provides, per capsule, nutrients including B12 as methylcobalamin 500 µg and folate as L-5-methyltetrahydrofolate 400 µg, with the authorised claim that riboflavin, niacin, pantothenic acid, vitamin B6, folate and vitamin B12 contribute to the reduction of tiredness and fatigue. These are targeted products, not multivitamins, and we sell no multivitamin at all.
Can a multivitamin do harm or push intake too high?
In COSMOS, the largest recent trial, researchers observed no safety concerns with a daily multivitamin over a median 3.6 years2. That is not the same as proof of no harm: the 2026 rapid review of meta-analyses reported a higher risk of progression of age-related macular degeneration among multivitamin users8.
The clearer danger sits with specific high-dose single nutrients. In the USPSTF review, beta carotene with or without vitamin A was associated with increased lung cancer risk (OR 1.20; 95% CI 1.01 to 1.42) and cardiovascular mortality (OR 1.10; 95% CI 1.02 to 1.19) in pooled trials of adults without cardiovascular disease or cancer4. A multivitamin is not automatically harmless either: stacking it on top of fortified foods and other supplements can push some nutrients above intended intakes. Vitamin D alone in pooled trials showed no mortality effect (OR 0.96; 95% CI 0.91 to 1.02)4, which is a reason to dose with intent rather than by habit.
When does a multivitamin make sense, and when does it not?
Whether food can close a gap comes first, a point we explore in can you get everything from food alone? It does not make sense as insurance against a poor diet, as a life extender, or as a substitute for a targeted nutrient when a real shortfall exists. For the broader supplement picture, see are food supplements worth taking?, whose verdict on multivitamins this article is consistent with.
Frequently Asked Questions
What did the studies measure on mortality?
No trial or cohort in well fed adults shows a mortality benefit. In three large US cohorts followed for up to 27 years, multivitamin use was not associated with lower all-cause mortality (HR 1.04; 95% CI 1.02 to 1.07 in the first half of follow-up)1, and COSMOS found no significant effect on all-cause mortality (HR 0.93)2.
Is the cancer evidence positive or negative?
Mostly null with small mixed signals. In COSMOS, total invasive cancer did not differ between the multivitamin and placebo groups (HR 0.97)2. In Linxian, total mortality did not differ in the whole group (HR 0.96)3.
How large were the memory differences?
In three COSMOS substudies the gap between groups was 0.06 to 0.07 standard deviation units, and COSMOS-Mind found no difference in new cases of mild cognitive impairment or dementia57.
Should I take a multivitamin if my diet is poor?
Fixing the diet comes first, because a multivitamin is not a fix for a poor diet and carries no fibre, protein or phytonutrients. A multivitamin does not reproduce what whole foods provide.
Does NOTFORTOMORROW sell a multivitamin?
No. We do not sell a multivitamin. We sell targeted supplements such as vitamin D3 + K2 drops and a bioactive B complex, each chosen for a specific nutrient and dose rather than broad coverage.
Can a multivitamin be harmful?
COSMOS observed no safety concerns over a median 3.6 years2, but a 2026 review linked multivitamin use to faster progression of age-related macular degeneration8. Beta carotene, found in some formulas, was linked to a higher lung cancer risk in pooled trials (OR 1.20)4. Stacking several supplements can also push total intake above intended levels.
The Bottom Line
Multivitamins are not worth it as life insurance. In the large trials, mortality, cardiovascular disease and total cancer did not differ between well fed adults on a multivitamin and those on placebo or no supplement12. In COSMOS-Mind, new cases of dementia did not differ between groups7. Where a shortfall is documented, the useful question is which single nutrient is missing, not whether to take a broad pill. We do not sell a multivitamin, and the evidence as it stands does not argue that we should.
Sources
- Multivitamin Use and Mortality Risk in 3 Prospective US Cohorts, JAMA Network Open, 2024
- Multivitamins in the prevention of cancer and cardiovascular disease: the COSMOS randomized clinical trial, The American Journal of Clinical Nutrition, 2022
- Mortality after multivitamin supplementation: Nearly 35-year follow-up of the randomized Linxian Dysplasia Nutrition Intervention Trial, Cancer, 2022
- Vitamin and Mineral Supplements for the Primary Prevention of Cardiovascular Disease and Cancer: Updated Evidence Report for the USPSTF, JAMA, 2022
- Effect of multivitamin-mineral supplementation versus placebo on cognitive function: COSMOS-Clinic results and meta-analysis of 3 COSMOS cognitive studies, The American Journal of Clinical Nutrition, 2024
- Multivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial, The American Journal of Clinical Nutrition, 2023
- Impact of multivitamin-mineral and cocoa extract on incidence of mild cognitive impairment and dementia: COSMOS-Mind, Alzheimer's & Dementia, 2023
- Multivitamin and mineral use: A rapid review of meta-analyses on health outcomes, Ageing Research Reviews, 2026
