Micronutrients: The Vitamins and Minerals Your Body Can't Make Itself

What Are Micronutrients?

Micronutrients are vitamins and minerals that the body requires in relatively small amounts but cannot manufacture on its own — or cannot make in sufficient quantities. That means they must come from food, beverages, or in some cases supplementation. Unlike macronutrients like carbohydrates, protein, and fat, micronutrients provide no calories. Instead, they serve as co-factors and regulators — enabling virtually every metabolic process that keeps the body functioning.

There are two broad categories:

• Vitamins — organic compounds grouped into fat-soluble (A, D, E, K) and water-soluble (C and the eight B vitamins). Fat-soluble vitamins are stored in body fat and the liver; water-soluble ones are not stored as readily and require more consistent dietary intake.
• Minerals — inorganic elements divided into macrominerals (needed in larger amounts, such as calcium and magnesium) and trace minerals (needed in very small amounts, such as iron, zinc, and selenium).

Understanding the difference matters for everyday eating decisions. For a broader look at how micronutrients fit alongside macros and meal planning, see building a balanced plate.

Key Vitamins: Roles and Dietary Sources

Below is a reference overview of the most nutritionally significant vitamins, what they do, and where to find them in food.

Fat-Soluble Vitamins

• Vitamin A — Supports vision (especially in low light), immune function, and cell growth. Found in liver, dairy, eggs, and as beta-carotene in orange and yellow vegetables like carrots and sweet potatoes.
• Vitamin D — Regulates calcium absorption and supports bone density and immune function. The skin synthesizes it via sunlight exposure, but dietary sources include fatty fish (salmon, mackerel), egg yolks, and fortified foods.
• Vitamin E — Acts as an antioxidant, helping protect cells from oxidative stress. Present in nuts, seeds, sunflower oil, and leafy greens.
• Vitamin K — Essential for blood clotting and plays a role in bone metabolism. Found in dark leafy greens (kale, spinach, broccoli) and some fermented foods.

Water-Soluble Vitamins

• Vitamin C — Supports collagen synthesis, immune defense, and acts as an antioxidant. Citrus fruits, bell peppers, strawberries, and broccoli are reliable sources.
• B Vitamins (B1, B2, B3, B5, B6, B7, B9, B12) — Collectively support energy metabolism, red blood cell formation, nervous system function, and DNA synthesis. Sources span whole grains, legumes, meat, eggs, dairy, and leafy greens. Vitamin B12 is found almost exclusively in animal products, making it a nutrient of particular attention for those following plant-based diets.

Essential Minerals: What They Do and Where to Get Them

Minerals perform structural and regulatory roles — from building bones to transmitting nerve signals. Here are the most critical ones:

Macrominerals

• Calcium — The most abundant mineral in the body, primarily stored in bones and teeth. Also involved in muscle contraction and nerve transmission. Sources: dairy products, fortified plant milks, leafy greens, almonds, tofu made with calcium sulfate.
• Magnesium — Involved in over 300 enzymatic reactions, including energy production and muscle function. Found in nuts, seeds, whole grains, dark chocolate, and leafy greens.
• Potassium — Helps regulate fluid balance and blood pressure, and supports heart and muscle function. Bananas, potatoes, avocados, beans, and dairy are good sources.
• Phosphorus — Works with calcium to build strong bones; also vital for energy storage (ATP). Widely present in protein-rich foods including meat, fish, eggs, and legumes.

Trace Minerals

• Iron — Central to hemoglobin, which carries oxygen in the blood. Heme iron (from meat, poultry, fish) is absorbed more efficiently than non-heme iron (from legumes, fortified grains). Pairing non-heme iron sources with vitamin C improves absorption.
• Zinc — Supports immune function, wound healing, and protein synthesis. Found in oysters, red meat, poultry, beans, nuts, and whole grains.
• Iodine — Required for thyroid hormone production, which regulates metabolism. Sources include iodized salt, seafood, dairy, and eggs.
• Selenium — Functions as an antioxidant and supports thyroid metabolism. Brazil nuts are an exceptionally concentrated source; fish, meat, and grains also contribute.

A consistently varied diet that includes balanced nutrition principles and a wide range of whole foods is generally the most practical way to meet mineral needs.

Gaps, Groups at Risk, and When to Consult a Professional

Even with a generally healthy diet, certain groups face a higher risk of specific micronutrient shortfalls. Pregnant individuals have elevated needs for folate (B9), iron, and iodine. Older adults often absorb vitamin B12 less efficiently. People avoiding animal products should pay close attention to B12, iron, zinc, calcium, vitamin D, and omega-3 fatty acids — see plant-based dietary sources for practical guidance on meeting needs from plants.

It is also worth noting that absorption of micronutrients is not simply a function of what you eat — hydration and digestive health also play a meaningful role. Certain medications, digestive conditions, and life stages can further affect how well the body uses what you consume.

This article is for general informational and educational purposes only and is not a substitute for professional medical or dietary advice. If you have concerns about nutrient deficiencies or your specific nutritional needs, consult a registered dietitian or qualified healthcare provider.