Vitamins and Minerals: A Plain-Language Reference

What Vitamins and Minerals Actually Are

Vitamins and minerals are collectively called micronutrients — nutrients your body needs in relatively small amounts compared to carbohydrates, protein, and fat, but that are absolutely essential for staying healthy. Unlike macronutrients, micronutrients don't provide calories; instead, they act as the tools your body uses to generate energy, build tissue, regulate hormones, and keep your immune system functioning. For a broader look at how macronutrients and micronutrients work together, see what carbs, proteins, and fats actually do.

There are two categories of vitamins:

• Fat-soluble vitamins (A, D, E, K) — stored in body fat and the liver; excess intake can accumulate over time.
• Water-soluble vitamins (C and the eight B vitamins) — not stored in significant amounts, so they need replenishing regularly through food.

Minerals are inorganic elements drawn from soil and water. Major minerals (like calcium, magnesium, and potassium) are needed in larger daily amounts, while trace minerals (like iron, zinc, and iodine) are needed in smaller quantities but are no less critical.

Key Vitamins: What They Do and Where to Find Them

Here's a plain-language rundown of the vitamins that matter most for everyday health:

• Vitamin A — supports vision (especially in low light), immune defense, and skin cell turnover. Found in liver, dairy, eggs, and as beta-carotene in orange and dark green vegetables like carrots and spinach.
• B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) — a family of eight that collectively support energy metabolism, red blood cell production, and nerve function. Whole grains, legumes, meat, eggs, and leafy greens cover most of them; B12 is found almost exclusively in animal products, making it a key concern for people following plant-based diets.
• Vitamin C — essential for collagen synthesis, wound healing, and immune function; also helps your body absorb iron from plant foods. Best sources include citrus, bell peppers, strawberries, and broccoli.
• Vitamin D — regulates calcium absorption and supports bone health, immune function, and muscle performance. Synthesized in skin exposed to sunlight; dietary sources include fatty fish, egg yolks, and fortified milk. Vitamin D deficiency is one of the most common nutrient gaps in the U.S.
• Vitamin E — an antioxidant that protects cells from oxidative damage. Found in nuts, seeds, vegetable oils, and wheat germ.
• Vitamin K — critical for blood clotting and bone metabolism. Leafy greens (kale, spinach, broccoli) are the richest sources.

For a compact lookup of these and more, see our micronutrients at a glance reference.

Key Minerals and the Nutrients Americans Often Fall Short On

Minerals do the structural and regulatory heavy lifting — from building bones to keeping your heartbeat steady. The USDA Dietary Guidelines consistently identify several nutrients as shortfall nutrients — meaning most Americans don't get enough from food alone:

• Calcium — the main structural mineral in bones and teeth; also involved in muscle contraction and nerve signaling. Dairy products, fortified plant milks, tofu made with calcium sulfate, and leafy greens are good sources.
• Iron — carries oxygen in red blood cells. Heme iron from meat is absorbed more efficiently than non-heme iron from plants; eating vitamin C alongside plant iron sources improves absorption. Teenage girls and women of childbearing age are at higher risk of deficiency.
• Magnesium — involved in over 300 enzyme reactions, including energy production and blood pressure regulation. Found in nuts, seeds, legumes, whole grains, and dark chocolate.
• Potassium — regulates fluid balance, nerve signals, and muscle contractions including the heart. Beans, potatoes, bananas, and leafy greens are reliable sources. Most Americans fall well below the adequate intake level.
• Zinc — supports immune function, wound healing, and protein synthesis. Meat, shellfish, legumes, and seeds are leading sources.
• Iodine — essential for thyroid hormone production. Iodized salt and seafood are the primary sources in the U.S. diet.

Understanding how nutrients are absorbed can also help — water plays a direct role in nutrient transport, covered in how hydration affects nutrition. And because dietary fiber interacts with mineral absorption (particularly calcium and iron), getting enough fiber from whole foods — rather than supplements — tends to deliver the best overall nutritional balance.

If you're unsure whether your current eating pattern covers your micronutrient needs, a registered dietitian can offer personalized guidance. Reading a nutrition label is also a practical starting point for spotting where your everyday diet may have gaps.

This article is for general informational and educational purposes only and is not a substitute for professional medical or dietary advice. Consult a qualified healthcare provider before making changes to your diet, particularly if you have a health condition or take medications.