Vitamins and minerals are nutrients your body needs in small amounts to function properly. Unlike macronutrients (carbs, protein, fat) which provide energy, vitamins and minerals act more like helpers -- they support processes like building strong bones (calcium), carrying oxygen in your blood (iron), fighting off illness (vitamin C), and helping you see in dim light (vitamin A). Your body cannot make most vitamins and minerals on its own, so you must get them from food. Eating a variety of foods from all five food groups is the best way to get enough of each one.
Focus on a handful of the most important vitamins and minerals rather than trying to memorize all of them. Connect each one to a concrete body function students can observe: calcium for bones, iron for energy, vitamin C for healing cuts, vitamin D for strong teeth. Have students look at food labels and identify which vitamins and minerals are listed. Compare the vitamin content of an orange, a glass of milk, and a piece of chicken to show that different foods provide different micronutrients.
You've learned about the three macronutrients -- carbohydrates, protein, and fat -- that your body needs in large amounts. Now meet the other team: vitamins and minerals, often called micronutrients because you need them in much smaller amounts. A few milligrams here, a few micrograms there. But don't let the small quantities fool you -- without them, your body cannot perform essential functions.
Vitamins are organic compounds (made by living things) that your body needs but mostly cannot produce on its own. There are 13 essential vitamins, and each has a specific job. Vitamin A helps you see, especially in low light. The B vitamins help your body convert food into energy. Vitamin C helps your body heal cuts and fight off infections. Vitamin D helps your body absorb calcium so your bones grow strong. Vitamins come in two categories: fat-soluble (A, D, E, K) dissolve in fat and can be stored in your body, while water-soluble (C and the B vitamins) dissolve in water and pass through more quickly, which means you need them more regularly.
Minerals are inorganic elements (from rocks, soil, and water) that plants absorb from the ground and animals get by eating plants. Calcium builds bones and teeth. Iron helps your red blood cells carry oxygen to every part of your body -- when you don't get enough iron, you feel tired and weak. Potassium helps your muscles and nerves work properly. Zinc helps your immune system fight off germs. Like vitamins, each mineral has specific roles that the others cannot fill.
The best way to get your vitamins and minerals is through food, not pills. An orange gives you vitamin C, but it also gives you fiber, water, and other beneficial compounds. A glass of milk gives you calcium, but also protein and vitamin D. Foods deliver nutrients in combinations that work together -- scientists call these synergies. A vitamin pill gives you isolated nutrients without the full support system. Pills have their place (some people have deficiencies that require supplements), but they are not a substitute for eating well.
Here's something that surprises many people: more is not always better. While water-soluble vitamins are hard to overdose on (your body flushes the excess), fat-soluble vitamins like A and D can accumulate to harmful levels. This is another reason whole foods are safer than mega-dose supplements -- it's nearly impossible to overdose on vitamin A by eating carrots, but quite possible by taking too many supplement pills.