Micronutrients at a Glance: A Plain-English Reference for Common Vitamins and Minerals
| Vitamins in human nutrition | 13 essential vitamins (National Institutes of Health, Office of Dietary Supplements) |
| Essential dietary minerals | ~16 recognized minerals (Dietary Reference Intakes, National Academies) |
| Fat-soluble vitamins | A, D, E, K |
| B12 deficiency risk group | Adults following strict plant-based diets (NIH Office of Dietary Supplements) |
| Iron absorption enhancer | Vitamin C (paired with plant-based iron sources) (Academy of Nutrition and Dietetics) |
| Primary bone mineral | Calcium (99% stored in bones and teeth) (NIH Office of Dietary Supplements) |
What Micronutrients Are and Why They Matter
Vitamins and minerals are collectively called micronutrients — nutrients the body needs in relatively small amounts but cannot function well without. Unlike carbohydrates, proteins, and fats (the macronutrients), micronutrients don't supply calories. Instead, they act as enablers: supporting enzyme activity, immune response, bone structure, nerve signaling, and hundreds of other processes happening constantly in your body.
Most people get a working overview of macros before they explore micros. If you haven't yet, the macronutrients primer is a useful starting point. This reference focuses on the vitamins and minerals that come up most in everyday nutrition conversations — organized so you can look up what you need, when you need it.
Micronutrient
A vitamin or mineral required by the body in relatively small amounts. Micronutrients do not provide energy (calories) but are essential for virtually every physiological process.
Fat-soluble vitamin
A vitamin (A, D, E, or K) that dissolves in fat and can be stored in the body's fatty tissues and liver. Because they accumulate, excessive intake from supplements can be problematic.
Water-soluble vitamin
A vitamin (C or any B vitamin) that dissolves in water and is not stored to a significant degree in the body. Excess amounts are generally excreted in urine, and regular dietary intake is important.
Trace mineral
A mineral the body needs in very small amounts (milligrams or micrograms), such as iron, zinc, or iodine. Despite the small quantities required, deficiency has significant health consequences.
Bioavailability
The proportion of a nutrient that the body actually absorbs and uses after consumption. Bioavailability varies by food source, preparation method, and what else is eaten at the same meal.
Recommended Dietary Allowance (RDA)
The average daily intake level sufficient to meet the nutrient requirements of nearly all (97–98%) healthy individuals in a given age and sex group, established by the National Academies of Sciences, Engineering, and Medicine.
The Key Vitamins: What Each One Does and Where to Find It
Vitamins fall into two broad categories: fat-soluble (A, D, E, K) and water-soluble (C and the B vitamins). Fat-soluble vitamins are stored in body tissue; water-soluble vitamins are not, which means regular dietary intake matters more for the latter group.
| Vitamins in human nutrition | 13 essential vitamins (National Institutes of Health, Office of Dietary Supplements) |
| Essential dietary minerals | ~16 recognized minerals (Dietary Reference Intakes, National Academies) |
| Fat-soluble vitamins | A, D, E, K |
| B12 deficiency risk group | Adults following strict plant-based diets (NIH Office of Dietary Supplements) |
| Iron absorption enhancer | Vitamin C (paired with plant-based iron sources) (Academy of Nutrition and Dietetics) |
| Primary bone mineral | Calcium (99% stored in bones and teeth) (NIH Office of Dietary Supplements) |
Fat-Soluble Vitamins
- Vitamin A — Supports vision, immune function, and skin cell turnover. Found in liver, eggs, dairy, and as beta-carotene in orange and leafy green vegetables.
- Vitamin D — Regulates calcium absorption and supports bone health and immune signaling. Synthesized via sunlight exposure; dietary sources include fatty fish, fortified dairy, and egg yolks.
- Vitamin E — Acts as an antioxidant, protecting cells from oxidative damage. Found in nuts, seeds, and vegetable oils.
- Vitamin K — Essential for blood clotting and bone metabolism. Leafy greens are the richest source; fermented foods supply a distinct form called K2.
Water-Soluble Vitamins
- Vitamin C — Supports collagen synthesis, immune defense, and iron absorption. Citrus, bell peppers, broccoli, and strawberries are strong sources.
- B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) — This group of eight vitamins supports energy metabolism, red blood cell production, and nervous system function. Whole grains, legumes, meat, fish, dairy, and eggs collectively cover the range. B12 is found almost exclusively in animal products, making it a key nutrient to monitor on plant-based diets.
The Key Minerals: Functions and Food Sources
Minerals are inorganic elements absorbed from the food you eat. Macrominerals (needed in larger amounts) include calcium, magnesium, phosphorus, sodium, and potassium. Trace minerals (needed in smaller amounts) include iron, zinc, iodine, selenium, and manganese.
Macrominerals to Know
- Calcium — The primary mineral in bones and teeth; also involved in muscle contraction and nerve transmission. Dairy, fortified plant milks, tofu made with calcium sulfate, and leafy greens are reliable sources.
- Magnesium — Involved in more than 300 enzymatic reactions, including energy production and muscle function. Found in nuts, seeds, legumes, dark chocolate, and whole grains.
- Potassium — Regulates fluid balance and supports healthy blood pressure. Bananas, potatoes, beans, and avocados are well-known sources.
Trace Minerals to Know
- Iron — Carries oxygen in red blood cells. Heme iron (from meat and fish) is absorbed more readily than non-heme iron (from legumes and leafy greens); pairing plant iron sources with vitamin C improves absorption.
- Zinc — Supports immune function, wound healing, and DNA synthesis. Oysters, red meat, poultry, beans, and pumpkin seeds are good sources.
- Iodine — Required for thyroid hormone production. Seafood, dairy, and iodized salt are the main dietary contributors.
For a deeper look at how these nutrients fit into an overall eating pattern, see The Science of Eating Well, and use reading a nutrition label to spot micronutrient content on packaged foods.
This article is for general informational and educational purposes only and is not a substitute for professional medical or dietary advice. Consult a registered dietitian or qualified healthcare provider before making significant changes to your diet or starting any supplement.