Who needs a multivitamin

A multivitamin is insurance against small gaps in your diet: useful when dieting, eating the same foods or training hard.

• Once a day with food (that's how fat-soluble A, D, E, K absorb).
• Don't stack several multis — you can overdo vitamin A and iron.
• Athletes most often lack vitamin D, magnesium, iron (women) and omega-3 — you can also take those individually.

Vitamins don't 'give' energy: if you're tired, check sleep, food and blood tests.