Multivitamin Guide (2026): Do You Actually Need One?
Multivitamin = a single pill combining most essential vitamins and minerals; a multivitamin-mineral or MVM in the research literature.
Not medical advice — this summarizes published research; talk to a clinician before starting a supplement. Methodology.
Most healthy adults eating a varied diet do not need a multivitamin — the large trials found no reduction in mortality or heart disease. Take one if you eat a restricted diet, take a nutrient-depleting medication (PPIs, metformin), are pregnant or planning, are over 65, or are on a GLP-1 drug. If you do take one, the formula decides it: methylated B vitamins, no iron unless you need it, and third-party testing.
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Quick answer: for most healthy adults eating a varied diet, the evidence for multivitamins is mixed at best — the largest trials show no mortality or cardiovascular benefit. The clearest positive finding is cognitive: pooling the COSMOS cognitive substudies (5,203 adults aged 60+) found a benefit equivalent to slowing cognitive aging by about 2 years. Multivitamins are also genuinely useful for restricted diets, medication-induced nutrient depletion, pregnancy, and GLP-1 drug use. If you take one, look for methylated B vitamins (not folic acid or cyanocobalamin), no iron unless needed, and third-party testing.
Should You Take a Multivitamin?
| Your situation | Multivitamin? | Why |
|---|---|---|
| Healthy, varied diet | Probably not | Test vitamin D instead; targeted supplements beat a broad multi |
| Vegan or vegetarian | Yes | B12 is the non-negotiable; D3, iron and zinc are the usual gaps |
| On a PPI or metformin | Yes | These deplete B12, magnesium, calcium, iron and vitamin C over time |
| On a GLP-1 drug | Yes | Much less food eaten means much less of everything in it |
| Pregnant or planning | Yes — a prenatal | Methylfolate (not folic acid), DHA, choline and iron |
| Over 65 | Reasonable | The one strong RCT signal: COSMOS, about 2 years less cognitive aging |
Do Multivitamins Actually Do Anything?
It depends entirely on the outcome you ask about, which is why the same trials get quoted to prove opposite things.
- Mortality and heart disease: no. This is consistent across every large trial and meta-analysis. A multivitamin will not make you live longer.
- Cognition in adults 60 and over: yes. COSMOS randomised 21,442 older adults, and cognition was measured in three substudies within it. Pooling those 5,203 participants, the benefit was equivalent to slowing cognitive aging by about 2 years. This is the strongest multivitamin result on record.
- Real dietary or medication-driven gaps: yes. If the nutrient is genuinely missing, replacing it works. That is not a claim about multivitamins so much as about deficiency.
The full trial-by-trial breakdown, including the COSMOS substudies and PHS-II, is in do you actually need a multivitamin.
Who Should Take a Multivitamin
| Your Situation | Multivitamin? | Better Alternative? |
|---|---|---|
| Healthy, varied diet | Probably not needed | Test for vitamin D deficiency. Consider magnesium if stressed. |
| Vegan or vegetarian | Yes — or targeted B12 + D3 + iron + zinc | Standalone B12 (methylcobalamin) is critical. Vitamin D3 often needed too. |
| On PPIs (omeprazole, etc.) | Yes — PPIs deplete multiple nutrients | See our PPI depletion guide — Mg, B12, calcium, iron, vitamin C all affected. |
| On GLP-1 drugs (Ozempic, Wegovy) | Yes — reduced food intake = reduced nutrient intake | GLP-1 supplement stack — protein + multi + biotin + collagen + magnesium. |
| Pregnant or planning | Yes — prenatal specifically | Prenatal multi with methylfolate (NOT folic acid), DHA, choline, iron. |
| Over 65 | Reasonable — absorption declines with age | COSMOS trial showed cognitive benefit for 65+. Ensure methylated B12. |
| Calorie-restricted diet | Yes — less food = fewer nutrients | Multi fills gaps; add vitamin D and magnesium at therapeutic doses. |
| Athlete | Optional | More important: creatine, magnesium, vitamin D, omega-3. |
What Should You Look For in a Multivitamin?
1. Methylated B Vitamins (Critical)
This is the single biggest quality differentiator in multivitamins:
- Folic acid (synthetic) must be converted to methylfolate (active) by your body using the MTHFR enzyme
- 30-40% of people have genetic MTHFR variants that impair this conversion
- Unmetabolized folic acid may accumulate and cause problems
- Look for: "methylfolate" or "5-MTHF" or "L-methylfolate" on the label
- Same issue with B12: "methylcobalamin" (active) vs "cyanocobalamin" (synthetic, requires conversion)
Cheap multivitamins use folic acid and cyanocobalamin because they are cheaper. Quality multivitamins use methylfolate and methylcobalamin. This alone accounts for most of the price spread between the cheapest and most expensive formulas we track.
2. Iron: Only If You Need It
- Who needs supplemental iron: premenopausal women (menstrual loss), pregnant women, vegans, people with chronic blood loss
- Who should avoid it: men, postmenopausal women, anyone with hemochromatosis
- Iron in excess is pro-oxidant and potentially harmful — it does not just pass through unused
- Best approach: Choose a multi without iron (like Thorne Basic Nutrients), and only add iron separately if blood work shows you need it
3. Third-Party Testing
Independent testing labs have found significant label inaccuracy in many multivitamins — some contain less than claimed, others contain undisclosed ingredients. Look for:
- USP Verified — tests for identity, potency, purity, dissolution. Gold standard for consumer supplements.
- NSF Certified for Sport — tests for 280+ banned substances. Essential for athletes.
- Products without third-party testing may or may not contain what the label claims — you have no way to verify.
What Is the Best Multivitamin?
Of the multivitamins we track and price:
| Product | Cost/Day | Certification | Key Features | Buy |
|---|---|---|---|---|
| NATURELO One Daily Multivitamin for Women | $0.40 | None | Whole-food multivitamin with methylated B vitamins, plant-based iron, D3, K2. $0 | Buy |
| Thorne Basic Nutrients 2/Day | $1.20 | NSF Certified for Sport | Comprehensive multivitamin with active B vitamins (methylfolate, methylcobalamin), chelated minerals, no iron. NSF Certified for Sport | Buy |
| Ritual Essential for Women 18+ Multivitamin | $1.23 | USP Verified | Targeted multivitamin with methylfolate, chelated iron, D3, omega-3 DHA, K2. USP Verified | Buy |
Full head-to-head deep dives in our best multivitamins comparison.
Multivitamin Guides
Do You Actually Need a Multivitamin?
The evidence from COSMOS, PHS-II, and other major trials. Who benefits, who doesn't, and what the data actually shows.
What to Look for in a Multivitamin (2026)
Methylated vs synthetic B vitamins. Iron: who needs it, who doesn't. Third-party testing. The 5 red flags that signal a cheap formulation.
Best Multivitamins (2026): Product Comparison
Every multivitamin we track, compared by ingredient quality, bioavailability, testing, and cost per day.
Best Multivitamin for Women
What actually differs in a women's formula (iron + folate), the iron rule that flips at menopause, and the folate point that matters before pregnancy.
Most Popular Multivitamin Brands: Are They Any Good?
Centrum, One A Day, and Nature Made are the best-selling drugstore brands — but popular isn't the same as well-formulated. How they compare to tested picks like Thorne.
Thorne vs Ritual Multivitamin
Thorne Basic Nutrients 2/Day vs Ritual Essential, compared on iron, certification, and cost per day. Nearly the same price — the formula decides it.
Frequently Asked Questions
Do I need a multivitamin?
If you eat a varied diet: probably not — the large trials found no mortality or cardiovascular benefit. If you have a restricted diet, take nutrient-depleting medications (PPIs, metformin), are pregnant, over 65, or on GLP-1 drugs: yes. For everyone else, targeted supplements (vitamin D, magnesium) often make more sense.
Do multivitamins actually do anything?
For mortality and heart disease, no. For cognition in adults 60+, yes — pooling the COSMOS cognitive substudies (5,203 participants) found a benefit equivalent to slowing cognitive aging by about 2 years. For pregnancy and genuine dietary gaps, yes. Details in do you actually need a multivitamin.
What should I look for in a multivitamin?
Three things: (1) Methylated B vitamins (methylfolate, not folic acid; methylcobalamin, not cyanocobalamin). (2) No iron unless you specifically need it. (3) Third-party testing (USP or NSF).
What is the best multivitamin?
Quality: Thorne Basic Nutrients 2/Day ($1.20/day, NSF Certified for Sport, methylated Bs, no iron). Value: NATURELO One Daily Multivitamin for Women ($0.40/day). Women: Ritual Essential for Women 18+ Multivitamin ($1.23/day, USP Verified, includes iron + DHA).
How much does a good multivitamin cost per day?
Across the multivitamins we price, cost per day runs from about $0.40 to $1.23. Price tracks ingredient form more than brand — the cheap end uses folic acid and cyanocobalamin, the higher end uses methylfolate and methylcobalamin plus third-party certification.
Related Guides
- Best Magnesium — Often more impactful than a multi for specific deficiency
- Best Vitamin D — Test first, supplement if needed
- PPI Nutrient Depletion Guide — If you take omeprazole/Nexium
- GLP-1 Supplement Stack — If you're on Ozempic/Wegovy
- Always Tired? — Deficiency-driven fatigue
Compare Multivitamin Products by Cost Per Day
If you're ready to buy, here's how the multivitamin products we track and verify compare on cost per day.
| Product | Dose/Serving | Servings | Price | Cost/Day | Certification | Buy |
|---|---|---|---|---|---|---|
| NATURELO One Daily Multivitamin for Women Best Value | 0multi | 60 | $23.95 | $0.40 | None | Buy on Amazon |
| Thorne Basic Nutrients 2/Day Quality Pick | 0multi | 30 | $36.00 | $1.20 | NSF Certified for Sport | Buy on Amazon |
| Ritual Essential for Women 18+ Multivitamin | 0multi | 30 | $36.98 | $1.23 | USP Verified | Buy on Amazon |