| Total essential vitamins | 13 (National Institutes of Health (NIH)) |
| Fat-soluble vitamins | A, D, E, K |
| Water-soluble vitamins | C and 8 B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) |
| Commonly under-consumed nutrients (U.S.) | Vitamin D, calcium, potassium (USDA Dietary Guidelines for Americans) |
| Essential minerals recognized | At least 15 (National Academy of Medicine) |
| Iron absorption tip | Pair plant-based iron sources with vitamin C to improve absorption (Academy of Nutrition and Dietetics) |
What Micronutrients Are and Why They Matter
Your body runs on two broad categories of nutrients: macronutrients — carbohydrates, protein, and fat — and micronutrients, which are the vitamins and minerals needed in smaller amounts but no less critical to your health. Unlike macronutrients, which provide energy, micronutrients act as co-pilots: they regulate enzyme activity, support immune defense, enable nerve signaling, and help convert food into usable fuel. See our overview of macronutrients to understand how the two categories work together.
The defining characteristic of essential micronutrients is that the human body cannot synthesize them in sufficient quantities on its own — they must come from food (or, when necessary, supplementation under a healthcare provider's guidance). There are 13 essential vitamins and at least 15 essential minerals recognized by nutritional science.
Micronutrient
A vitamin or mineral required by the body in relatively small amounts to support normal physiological function. Unlike macronutrients, micronutrients do not directly provide energy (calories).
Essential nutrient
A nutrient the human body cannot produce in adequate quantities on its own and must therefore obtain through diet or supplementation.
Fat-soluble vitamin
A vitamin (A, D, E, or K) that is absorbed alongside dietary fat and stored in the body's fatty tissues and liver, meaning both deficiency and toxicity are possible over time.
Water-soluble vitamin
A vitamin (C or any of the eight B vitamins) that dissolves in water, is not stored significantly in the body, and is largely excreted when consumed in excess. Regular dietary intake is important.
Trace mineral
A mineral required by the body in very small amounts — typically micrograms to a few milligrams per day — such as iron, zinc, iodine, and selenium.
Heme iron
A form of iron found in animal-based foods (particularly red meat and shellfish) that is more readily absorbed by the human digestive system than non-heme iron from plant sources.
This article is general nutrition education and does not constitute medical advice. If you suspect a deficiency or have specific health concerns, consult a qualified healthcare professional.
Key Vitamins: Functions and Food Sources
Vitamins fall into two groups based on how the body stores them:
- Fat-soluble vitamins (A, D, E, K) are stored in body fat and the liver. They can accumulate over time, so both deficiency and excess are possible.
- Water-soluble vitamins (C and the eight B vitamins) are not stored in significant amounts; excess is generally excreted in urine, which means consistent daily intake matters most.
| Total essential vitamins | 13 (National Institutes of Health (NIH)) |
| Fat-soluble vitamins | A, D, E, K |
| Water-soluble vitamins | C and 8 B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) |
| Commonly under-consumed nutrients (U.S.) | Vitamin D, calcium, potassium (USDA Dietary Guidelines for Americans) |
| Essential minerals recognized | At least 15 (National Academy of Medicine) |
| Iron absorption tip | Pair plant-based iron sources with vitamin C to improve absorption (Academy of Nutrition and Dietetics) |
Spotlight on Common Gaps
The USDA's dietary guidelines consistently identify vitamin D, calcium, and potassium as nutrients many Americans under-consume. Vitamin D is unique because the body can produce it through sun exposure, yet geographic location, skin tone, and indoor lifestyles make food and supplementation important considerations for many people. Fatty fish, egg yolks, and fortified dairy or plant-based milks are practical food sources.
B vitamins — particularly B12 and folate — deserve attention because they support red blood cell formation and neurological function. B12 is found almost exclusively in animal-derived foods, making it a key consideration for people following plant-based diets. Folate, found abundantly in leafy greens and legumes, is especially critical during pregnancy; always consult a healthcare provider for guidance specific to pregnancy.
Essential Minerals and Where to Find Them
Minerals are inorganic elements sourced from soil and water, which means they enter the food supply through plants and the animals that eat those plants. They serve structural roles (calcium and phosphorus in bones) and regulatory ones (iron carrying oxygen in red blood cells, magnesium supporting hundreds of enzymatic reactions).
A helpful way to think about minerals is by the amount your body needs:
- Macrominerals (needed in larger amounts): calcium, phosphorus, magnesium, sodium, potassium, chloride, sulfur.
- Trace minerals (needed in smaller amounts): iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium, molybdenum.
Iron deficiency is among the most common nutrient shortfalls worldwide, particularly in women of reproductive age, according to the World Health Organization. Red meat and shellfish provide heme iron, which the body absorbs readily. Plant-based sources like lentils, tofu, and spinach provide non-heme iron, which is less readily absorbed — pairing them with a vitamin C–rich food (such as citrus or bell peppers) can meaningfully improve absorption.
Iodine is essential for thyroid hormone production but is easy to overlook. Iodized salt and seafood are the most reliable sources in the U.S. diet. Understanding why calorie totals alone don't capture nutritional quality helps explain why micronutrient density matters as much as energy intake.
~1 in 3
People globally affected by micronutrient deficiency
According to the World Health Organization, micronutrient deficiencies — sometimes called 'hidden hunger' — affect roughly a third of the global population.
40%
U.S. adults with insufficient vitamin D intake
Research published in nutrition surveillance data suggests a substantial portion of American adults do not meet recommended vitamin D intake levels from diet alone.
#1
Most common nutritional deficiency worldwide
Iron deficiency is identified by the World Health Organization as the single most prevalent nutritional deficiency globally, particularly affecting women and young children.
Building a Micronutrient-Rich Eating Pattern
No single food provides every essential micronutrient, which is why dietary variety is the cornerstone of practical nutrition guidance. A few evidence-based strategies can help:
- Eat a wide range of colors. Different pigments in fruits and vegetables often signal different vitamins and antioxidants. Rotating produce choices throughout the week broadens your nutrient intake naturally.
- Don't skip food groups without a reason. Dairy and fortified alternatives supply calcium and vitamin D; whole grains contribute B vitamins and magnesium; lean proteins provide zinc and iron. Eliminating a category should be a deliberate, informed decision.
- Be cautious with supplements. Supplements can fill genuine gaps, but some micronutrients are harmful in excess. Before adding any supplement to your routine, discuss it with a healthcare provider. Our related reference explains what the major supplement types are and what research says about them.
- Consider how nutrients interact. Fat-soluble vitamins (A, D, E, K) are best absorbed when consumed with dietary fat. Calcium can reduce iron absorption when taken together in large amounts. These interactions are another reason whole-food sources generally outperform isolated supplements for day-to-day needs.
Staying well-hydrated also plays a supporting role — water is necessary for transporting nutrients throughout the body. Learn more about how hydration connects to everyday nutrition.
This article is intended for general informational and educational purposes only and is not a substitute for professional medical or dietary advice. Always consult a licensed healthcare provider or registered dietitian for guidance tailored to your individual health needs.
Supplement Use Requires Professional Guidance
While supplements can address genuine micronutrient gaps, they are not a replacement for a varied diet and some carry real risks at high doses. Fat-soluble vitamins in particular can accumulate to toxic levels. Before beginning any supplement regimen, speak with a registered dietitian or your primary care provider to determine whether supplementation is appropriate for your individual situation.