| Number of recognized vitamins | 13 essential vitamins (National Institutes of Health, Office of Dietary Supplements) |
| Macrominerals required by the body | 7 (calcium, phosphorus, magnesium, sodium, potassium, chloride, sulfur) (National Institutes of Health) |
| Most common micronutrient deficiency globally | Iron deficiency (World Health Organization) |
| Vitamin most often low in plant-based diets | Vitamin B12 (Academy of Nutrition and Dietetics) |
| Primary role of vitamin D | Facilitates calcium absorption; supports bone health and immune function (NIH Office of Dietary Supplements) |
| Fat-soluble vitamins | A, D, E, K |
What Are Micronutrients and Why Do They Matter?
Unlike macronutrients — carbohydrates, proteins, and fats — micronutrients are needed by the body in relatively small amounts. Yet their roles are anything but minor. Vitamins and minerals regulate hundreds of physiological processes, from converting food into usable energy to maintaining bone density, supporting immune function, and enabling proper nerve signaling.
The term micronutrient covers two broad categories: vitamins (organic compounds the body cannot produce in sufficient quantities on its own) and minerals (inorganic elements absorbed from food and water). Together, they fill functional gaps that macronutrients alone cannot address. For a broader foundation, see our introduction to nutrition basics.
Micronutrient
Vitamins and minerals required by the body in small amounts to support essential physiological functions. Unlike macronutrients, they provide no direct energy but are critical for metabolic processes.
Fat-Soluble Vitamin
Vitamins (A, D, E, K) that dissolve in fat and are stored in the body's fatty tissues and liver. Because they accumulate, excessive intake from supplements can be harmful.
Water-Soluble Vitamin
Vitamins (C and the B complex) that dissolve in water and are not stored in large quantities; excess amounts are generally excreted in urine, requiring more regular dietary replenishment.
Trace Mineral
A mineral the body requires in very small quantities — typically less than 100 mg per day — such as iron, zinc, iodine, and selenium. Despite the tiny amounts needed, deficiencies can have significant health consequences.
Antioxidant
A compound that helps neutralize unstable molecules called free radicals, potentially reducing oxidative stress on cells. Vitamins C and E are among the best-known dietary antioxidants.
Dietary Reference Intake (DRI)
A set of reference values established by scientific bodies to guide adequate nutrient intake for different population groups. DRIs include the Recommended Dietary Allowance (RDA) and Tolerable Upper Intake Level (UL), among others.
Key Vitamins: Functions and Food Sources
Vitamins are divided into two groups based on how they are stored and transported in the body.
Fat-Soluble Vitamins (A, D, E, K)
Vitamin A supports vision (particularly in low-light conditions), skin integrity, and immune defense. It is found preformed in liver and dairy, and as provitamin A (beta-carotene) in orange and dark leafy vegetables.
Vitamin D facilitates calcium absorption and plays a role in bone health and immune regulation. Fatty fish, fortified dairy, and egg yolks provide dietary sources; the skin also synthesizes it through sun exposure.
Vitamin E acts as an antioxidant, protecting cell membranes from oxidative damage. Nuts, seeds, and vegetable oils are primary sources.
Vitamin K is essential for blood clotting and bone metabolism. Leafy greens such as kale and spinach are among the richest sources.
Water-Soluble Vitamins (B Complex and C)
The B vitamins — including B1 (thiamine), B2 (riboflavin), B3 (niacin), B6, B12, folate, and others — collectively support energy metabolism, red blood cell formation, and neurological function. Whole grains, legumes, eggs, meat, and fortified cereals supply them across a varied diet.
Vitamin C is a well-known antioxidant that also aids collagen synthesis and enhances iron absorption from plant-based foods. Citrus fruits, bell peppers, and strawberries are concentrated sources.
Understanding how these nutrients appear on product labels can sharpen everyday food decisions — reading a nutrition label without getting confused covers that process in detail.
Essential Minerals: What They Do and Where to Find Them
Minerals are split into macrominerals (needed in larger amounts) and trace minerals (needed in very small quantities).
| Number of recognized vitamins | 13 essential vitamins (National Institutes of Health, Office of Dietary Supplements) |
| Macrominerals required by the body | 7 (calcium, phosphorus, magnesium, sodium, potassium, chloride, sulfur) (National Institutes of Health) |
| Most common micronutrient deficiency globally | Iron deficiency (World Health Organization) |
| Vitamin most often low in plant-based diets | Vitamin B12 (Academy of Nutrition and Dietetics) |
| Primary role of vitamin D | Facilitates calcium absorption; supports bone health and immune function (NIH Office of Dietary Supplements) |
| Fat-soluble vitamins | A, D, E, K |
Macrominerals
Calcium is the most abundant mineral in the body and is central to bone and tooth strength, muscle contraction, and nerve transmission. Dairy, fortified plant milks, leafy greens, and tofu are reliable sources.
Magnesium participates in more than 300 enzymatic reactions, including those involved in energy production and muscle relaxation. Whole grains, legumes, and nuts provide it readily.
Potassium helps regulate fluid balance and blood pressure, and supports normal muscle and heart function. Bananas, potatoes, beans, and dairy are good sources.
Trace Minerals
Iron is critical for hemoglobin production and oxygen transport. Red meat and shellfish supply highly absorbable heme iron; lentils, spinach, and fortified cereals offer non-heme iron, which is better absorbed alongside vitamin C.
Zinc supports immune function, wound healing, and DNA synthesis. Meat, shellfish, legumes, and pumpkin seeds are dependable sources.
Iodine is necessary for thyroid hormone production, which governs metabolism. Iodized salt and seafood are common dietary contributors.
Nutrient needs evolve throughout adulthood — how dietary needs shift across life stages explores this in more depth.
Getting Micronutrients Through Food — and Knowing When to Ask a Professional
For most healthy adults, a varied diet that includes vegetables, fruits, whole grains, legumes, dairy or fortified alternatives, and lean protein sources provides adequate amounts of the key vitamins and minerals. No single food does it all; dietary diversity is the practical path to broad micronutrient coverage.
Supplements can fill documented gaps — for instance, vitamin B12 for people following a strictly plant-based diet, or folate during pregnancy — but they are not a substitute for whole-food variety, and more is not always better. Fat-soluble vitamins, in particular, can accumulate to problematic levels in high-dose supplement form. Pairing your knowledge of micronutrients with good label literacy helps — decoding food packaging labels is a practical companion reference.
Micronutrient needs also interact with macronutrient intake in meaningful ways. Understanding what carbs, proteins, and fats do rounds out the picture of how nutrients work together.
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 your nutrient intake, symptoms of deficiency, or specific health conditions, consult a qualified healthcare provider or registered dietitian before making changes to your diet or supplement routine.