Supplements are like the apps of the nutrition and wellness world. Got a specific need? There's a supplement for that. Have to lose weight or gain muscle before beach season? Check. Suffering from stress or mood swings? Check. But not all supplements—or their manufacturers—are created equal. While there are plenty of products out there that deliver life-changing results, the industry is still blighted by latter-day snake-oil salesmen. And then there is that fast-moving target called science. Should every guy really take vitamin D? Depends on which study you read. Are you deficient in omega-3s? Most likely. And can you actually overdose on vitamins? Definitely. Before you negotiate the supplement aisle of your health-food store or even take your daily multivitamin, you'll want to consult this guide—the ultimate primer on healthy pill popping.

Vitamin Health Benefits & Food Sources
Do you know what vitamins A, B, C, D and E really do? And should you bother taking them?
There's a Supplement for That…
Find out which ones help you cheer up, increase libido, lose weight and build muscle.
5 Supplements Every Man Should Avoid