What they can fix
A multivitamin can help cover small gaps when your diet is inconsistent or restricted. It is cheap insurance against mild shortfalls, not a performance booster.
What they cannot fix
- A genuinely poor diet low in vegetables, protein, and variety.
- Low energy from under-eating or poor sleep.
- Specific deficiencies that need targeted amounts, like iron or vitamin D.
- Muscle growth, fat loss, or training performance directly.
Who might reasonably take one
People with a limited or repetitive diet, older adults, or those recovering from illness may benefit most. Avoid megadose products well above standard daily amounts, since more is not better for most vitamins and minerals.