What is the best multivitamin‑mineral supplement for a generally healthy adult with a varied diet?

There Is No "Best" Multivitamin—Healthy Adults with Varied Diets Do Not Need One

For generally healthy adults eating a varied diet, the evidence does not support routine multivitamin-mineral supplementation for disease prevention or overall health improvement. The U.S. Preventive Services Task Force concludes with insufficient evidence to recommend for or against multivitamins for preventing cardiovascular disease or cancer, and multiple randomized controlled trials show no effect on all-cause mortality 1, 2, 3.

The Evidence Against Routine Supplementation

The USPSTF issues a Grade D recommendation (recommendation against use) for β-carotene and vitamin E supplements because β-carotene increases lung cancer risk in smokers and those with asbestos exposure, while vitamin E provides no net benefit and may increase hemorrhage risk at high doses 1, 2, 3.

For all other single nutrients and multivitamin combinations, the evidence remains insufficient to determine any preventive benefit or harm for cardiovascular disease or cancer outcomes 1, 2.

When Supplementation IS Appropriate

Supplementation should be reserved for documented deficiencies or specific high-risk conditions 2:

• Pregnant women or those planning conception: Require 800-1,000 μg folic acid daily 1
• Older adults (>50 years) with reduced energy intake or poor dietary variety 4, 5
• Individuals with malabsorption conditions (bariatric surgery, inflammatory bowel disease) 1
• Strict vegetarians: May need vitamin B12 supplementation 1
• Individuals on calorie-restricted diets (<1,500 kcal/day) 1

If You Choose to Use a Multivitamin

If supplementation is pursued despite lack of evidence for benefit, select a standard formulation providing approximately 100% of the Recommended Dietary Allowance (RDA) for most nutrients 2, 5. Avoid formulations exceeding 100% RDA, particularly for fat-soluble vitamins (A, D, E, K), as these accumulate in the body and pose toxicity risks 1, 2.

Critical Safety Considerations

• Vitamin A: Moderate doses reduce bone mineral density; high doses are hepatotoxic and teratogenic 1, 2
• Vitamin D: Adverse effects occur above 4,000 IU/day (the tolerable upper intake level) 1, 2
• β-carotene: Absolutely contraindicated in smokers and those with asbestos exposure due to increased lung cancer risk 1, 2, 3
• Vitamin E: No benefit for disease prevention; doses >1,000 mg/day may increase hemorrhage risk 1, 2

The Optimal Approach

Prioritize obtaining nutrients through a balanced dietary pattern rather than supplementation 2, 4. Individuals consuming a varied diet that includes fruits, vegetables, whole grains, lean proteins, and dairy products will meet micronutrient needs without supplementation 1.

Common Pitfalls to Avoid

• Do not assume "more is better": Fat-soluble vitamins accumulate and can cause toxicity 1, 2
• Do not rely on supplements to compensate for poor diet: Supplements cannot replicate the complex nutritional benefits of whole foods 2, 4
• Do not use supplements marketed for "wellness" or "energy": These claims lack evidence and often contain excessive doses 2
• Do not assume supplements are harmless: The FDA does not require manufacturers to report adverse events, and quality control varies considerably 1, 6

Clinical Counseling Algorithm

When patients inquire about multivitamins 2:

1. Assess dietary intake: Calculate servings of fruits, vegetables, whole grains, protein sources, and dairy
2. Identify risk factors: Age >50, pregnancy, malabsorption, restrictive diets, chronic illness
3. If diet is adequate and no risk factors exist: Counsel that supplementation provides no proven benefit and may pose risks
4. If dietary intake is poor or risk factors present: Consider targeted supplementation for specific documented deficiencies rather than broad-spectrum multivitamins
5. If patient insists on supplementation: Recommend a standard formulation at 100% RDA, avoid β-carotene and high-dose vitamin E, and emphasize that this does not replace dietary improvement

The bottom line: There is no "best" multivitamin because healthy adults with varied diets do not benefit from routine supplementation 1, 2, 3.