Nutrient Teamwork

Some nutrients compete for absorption while others work as a team. Vitamin C sharply boosts iron absorption — a squeeze of lemon on your spinach can multiply how much iron you take in. Calcium and iron, though, fight over the same pathway, so separate those supplements by a couple of hours. And vitamin D helps you absorb calcium, which is why fortified milk pairs them.

Heat changes things too. Cooking unlocks more lycopene in tomatoes and beta-carotene in carrots, while vitamin C breaks down with heat. The simple fix: eat a mix of cooked and raw vegetables across the day.