Micronutrients at a Glance: Vitamins and Minerals Every Adult Should Know

What Are Micronutrients and Why Do They Matter?

Micronutrients are the vitamins and minerals your body needs in relatively small amounts to function properly. Unlike macronutrients like carbs, protein, and fat, micronutrients don't provide calories — but they are every bit as essential. They drive hundreds of biochemical reactions: helping your immune system fight off illness, enabling your nerves to fire correctly, keeping your bones dense, and allowing your body to convert food into usable energy.

Most adults get adequate micronutrients through a varied, whole-food diet. But certain groups — including older adults, pregnant individuals, and those following restrictive diets — face a higher risk of falling short. Understanding what each micronutrient does and where to find it is the foundation of eating well. For definitions of related nutrition terms, see our key nutrition terms reference.

Essential Vitamins: Roles and Food Sources

Vitamins are divided into two categories: fat-soluble (A, D, E, K), which are stored in body fat and liver, and water-soluble (C and the B vitamins), which are not stored and need regular replenishment through diet.

• Vitamin A: Supports vision, immune defense, and skin cell renewal. Found in liver, dairy, eggs, and orange-yellow vegetables like carrots and sweet potatoes.
• B Vitamins (B1, B2, B3, B6, B12, Folate): Collectively support energy metabolism, red blood cell production, and nervous system health. Whole grains, legumes, leafy greens, meat, fish, and dairy are primary sources. Vitamin B12 is found almost exclusively in animal products, making supplementation a common consideration for those following plant-based diets — always discuss this with a healthcare provider.
• Vitamin C: Powers collagen synthesis, wound healing, and antioxidant defense. Citrus fruits, bell peppers, strawberries, and broccoli are particularly rich sources.
• Vitamin D: Regulates calcium absorption and supports bone health and immune function. Fatty fish, fortified dairy, and egg yolks provide some; the body also synthesizes vitamin D from sunlight exposure, though many adults have insufficient levels.
• Vitamin E: Acts as an antioxidant and supports immune function. Nuts, seeds, vegetable oils, and spinach are good sources.
• Vitamin K: Essential for blood clotting and bone metabolism. Leafy green vegetables such as kale, spinach, and broccoli are the standout sources.

For a deeper look at how these vitamins interact with everyday foods, visit our micronutrients food reference guide.

Key Minerals: What They Do and Where to Find Them

Minerals are inorganic elements sourced entirely from food and water — your body cannot produce them. They fall into two groups: macrominerals (needed in larger amounts, such as calcium and magnesium) and trace minerals (needed in smaller quantities, such as iron and zinc).

• Calcium: Builds and maintains bone and tooth structure; also critical for muscle contraction and nerve signaling. Dairy products, fortified plant milks, tofu, and leafy greens are strong dietary sources.
• Iron: Central to hemoglobin, the protein in red blood cells that carries oxygen. Red meat, poultry, lentils, and fortified cereals supply iron; pairing plant-based iron sources with vitamin C improves absorption.
• Magnesium: Involved in over 300 enzymatic reactions, including energy production, muscle function, and blood sugar regulation. Nuts, seeds, whole grains, and dark chocolate are good sources.
• Potassium: Helps regulate fluid balance, nerve signals, and blood pressure. Bananas, potatoes, beans, and leafy greens are reliable sources.
• Zinc: Supports immune function, wound healing, and DNA synthesis. Meat, shellfish, legumes, and pumpkin seeds are notable sources.
• Iodine: Essential for thyroid hormone production, which governs metabolism. Iodized salt, dairy, and seafood are the primary sources in the American diet.

This article is part of our broader Healthy Eating Basics resource hub, where you can explore balanced meal planning and nutrition fundamentals.

This article is for general informational purposes only and is not a substitute for professional medical or dietary advice. Consult a qualified healthcare provider before making significant changes to your diet or taking supplements.