What are Micronutrients?

In order to maintain your muscles, bones, brain, nerves, skin, circulatory and immune systems, your body needs a constant supply of different raw materials. These materials include both macronutrients – fats, proteins, and carbohydrates – and the equally-important micronutrients – vitamins and minerals. While macronutrients act as the building blocks for all foods, micronutrients fill any gaps left behind. Because our bodies can’t produce micronutrients, they must be obtained through the foods we eat; that's why micronutrients are often referred to as essential nutrients. Micronutrients are vital for growth, proper immune function, brain development, disease prevention, and many other important bodily functions.

Micronutrients are the vitamins and minerals that your body only needs in very small amounts. Their impact on your health is critical, and while imbalances and deficiencies aren’t uncommon, micronutrient deficiencies can cause dangerous health conditions. They most often result in feelings of low energy and brain fog, leading to lower test scores for students, reduced work productivity for adults, and increased risk of contracting other diseases and developing health conditions. Luckily, these deficiencies are often treated with dietary changes or supplements.

Types of Micronutrients

Micronutrients are divided into four categories: water-soluble vitamins, fat-soluble vitamins, macrominerals, and trace minerals.

Water-soluble vitamins

Water-soluble vitamins are considered short-term vitamins, as they don’t get stored in your body like fat-soluble vitamins. Instead, they enter your bloodstream, and then anything that isn’t absorbed or needed by your body is eliminated through your urine. Since water-soluble vitamins don’t last long in the body, they need to be replenished frequently. Water-soluble vitamins include the B vitamins – thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folate/folic acid, and cobalamin – and vitamin C.

As a group, B vitamins fuel your body by creating the energy you need to get through the day. B vitamins also help your body metabolize fats and proteins. They’re necessary for a functional nervous system, as well as healthy hair, skin, eyes, and a healthy liver. Many B vitamins are destroyed with high-heat cooking or long cooking times. This is why some foods that have undergone processing, like cereal are enriched with vitamins.

Thiamin / B1: Vitamin B1 plays a vital role in the growth and function of various cells.

• Food sources: Meats, fish, whole grains, legumes, fortified cereals and breads, and baby formula
• Recommended daily allowance (RDA): 2 milligrams (mg) and 1.1 mg for men and women, respectively

Riboflavin / B2: Vitamin B2 is an important vitamin for breaking down food, absorbing other nutrients, and maintaining your body’s energy supply.

• Food sources: Eggs, meats, fish, poultry, cruciferous vegetables, nuts, and dairy products
• RDA: 3 mg and 1.1 mg for men and women, respectively

Niacin / B3: Vitamin B3 helps to convert nutrients into energy, create cholesterol and fats, create and repair DNA, and works as an antioxidant to protect your body from free radicals.

• Food sources: Red meats, poultry, fish, brown rice, nuts, seeds, legumes, and bananas
• RDA: 16 mg and 14 mg for men and women, respectively

Pantothenic acid / B5: Vitamin B5 is needed to synthesize cholesterol and is critical for the creation of stress and sex hormones produced in the adrenal glands. Pantothenic acid gets its name from the Greek word pantos, meaning “everywhere,” because it’s available in many foods.

• Food sources: Cauliflower, corn, avocado, lentils, sweet potatoes, salmon, organ meats, and more
• RDA: 6 mg daily, regardless of sex

Pyridoxine / B6: Vitamin B6 is important for brain development and for keeping the immune and nervous systems healthy.

• Food sources: Poultry, fish, potatoes, chickpeas, tuna, papayas, beef liver, and dark leafy greens
• RDA: 3 mg daily, regardless of sex

Biotin / B7: Like other B vitamins, vitamin B7 is needed to metabolize macronutrients and amino acids. It’s commonly marketed as a hair, skin, and nail supplement, but biotin is also a critical nutrient during pregnancy.

• Food sources: Egg yolks, soybeans and other legumes, whole grains, nuts and nut butters, cauliflower, and mushrooms
• Adequate intake level (AI): 30 micrograms (mcg) daily, regardless of sex

Folate / Folic acid / B9: Folate is the natural form of vitamin B9, helping to form DNA and RNA, and working to properly metabolize protein. Folic acid is a synthetic form of folate that is often added back into cooked or processed foods. Unfortunately, your body does not convert folic acid into folate very well, so unmetabolized folic acid may build up in your bloodstream. Like biotin, folate is needed during pregnancy to ensure the proper development of the fetus.

• Food sources: Dark leafy greens, liver, seafood, fresh fruit, peanuts, and beans
• RDA: 400 mcg for people 19 and older, 600 mcg during pregnancy

Cobalamin / B12: Vitamin B12 contains cobalt, and compounds within vitamin B12 are collectively referred to as cobalamins. Vitamin B12 is necessary for a healthy central nervous system, proper red blood cell formation, and the production of DNA.

• Food sources: Vitamin B12 is not found in plant foods – only sources like poultry, red meat, fish, and eggs contain the vitamin – so people following a plant-based diet are more likely to experience a vitamin B12 deficiency.
• RDA: 4 mcg daily, regardless of sex

Ascorbic acid / Vitamin C: Ascorbic acid is essential for proper wound healing, infection control, making collagen, and forming blood vessels, cartilage, and bones. As an antioxidant, vitamin C also protects your body against the free radicals that play a role in heart disease, cancer, and other metabolic disorders.

• Food sources: Citrus (including oranges, kiwi, lemons, and grapefruit), bell peppers, tomatoes, strawberries, cruciferous vegetables, and white potatoes
• RDA: 90 mg and 75 mg for men and women, respectively, with an additional 35 mg suggested for people whole smoke, as tobacco can deplete vitamin C levels in the body

Fat-soluble vitamins

Fat-soluble vitamins – unlike their water-soluble counterparts – do not dissolve in water. Instead, they bind to the fats in foods and are processed by your body the same way that fats are. Fat-soluble vitamins don’t disappear when the foods they’re in are processed or cooked, and your body stores them in the liver and fat tissue when not being used. Fat-soluble vitamins include vitamins A, D, E, and K.

Vitamin A / Retinol: Vitamin A plays an important role in bone health (including your teeth), reproductive health, proper gene division and cell reproduction, and regulation of the immune system. Through our diet, we get vitamin A in two forms: preformed vitamin A (retinol, retinyl esters), and provitamin A carotenoids (like beta-carotene) that are converted to retinol. Preformed vitamin A comes from animal products, fortified foods, and vitamin supplements, while provitamin A carotenoids are found naturally in plant foods.

• Foods sources: Leafy green vegetables, milk, eggs, fish oils, tomatoes, and orange and yellow vegetables
• RDA: 3,000 international units (IU) and 2,333 IU for men and women, respectively

Vitamin D: Vitamin D is essential for maintaining healthy bones and teeth as well as supporting your brain, immune system, and nervous system health. Despite being called a vitamin, vitamin D is a prohormone or hormone precursor. It plays a crucial role in regulating skin-cell growth, enhancing your skin’s natural immune system, and helping to destroy free radicals that can cause premature aging.

• Food sources: Fish, yogurt, eggs, and red meats
• RDA: 600 IU for people under 70 and 800 IU for those over 70

Vitamin E / Tocopherol: By acting as an antioxidant, vitamin E protects vitamins A and C, red blood cells, and essential fatty acids from being destroyed in the body.

• Food sources: Vegetable oils (soybean, corn, cottonseed, safflower), grains, nuts and seeds, fortified cereals, pumpkin, asparagus, avocado, and mango
• RDA: 15 mg daily, regardless of sex, 19 mg daily while breastfeeding

Vitamin K: Vitamin K is actually a group of compounds that include vitamin K1 and vitamin K2. Both types are important for building bones and proper blood clotting.

• Food sources: Vitamin K1 - leafy greens, soybeans, and fortified foods; Vitamin K2 - meats, cheeses, and eggs
• AI: 120 mcg and 90 mcg for men and women, respectively

Macrominerals

Macrominerals are minerals your body needs in larger amounts (relative to trace minerals). They’re crucial for muscle and bone health and play a role in controlling blood pressure. Macrominerals include calcium, phosphorus, magnesium, sodium, chloride, potassium, and sulfur.

Calcium: Calcium is the most abundant mineral in the body. It’s used to build bones and teeth, and as a messenger in cell signaling. Your bones work as a calcium reserve, storing excess calcium in case you become deficient.

• Food sources: Milk, cheese, yogurt, leafy green vegetables, edamame, winter squash, almonds, canned sardines
• RDA: 1,000 mg for those under 70 and 1,200 mg for those over 70

Phosphorus: Along with calcium, phosphorus works to keep your bones healthy. Phosphorus helps activate various enzymes, keeps your blood pH within normal range, regulates the function of muscles and nerves (including our hearts!) and is a building block of our genes.

• Food sources: Red meat, poultry, dairy products, seafood, legumes, nuts, whole grains, and seeds
• RDA: 700 mg daily, regardless of sex

Magnesium: Magnesium is mainly used for metabolic processes, cell signaling and migration, and is a structural component of chromosomes and cell membranes.

• Food sources: Figs, brown rice, soybeans, leafy greens, nuts and nut butters, squash and pumpkin seeds, and dark chocolate
• RDA: 400-420 mg and 310-320 mg for men and women, respectively

Sodium: Sodium maintains proper nerve and muscle function; along with potassium, sodium is the most important electrolyte mineral in your body. Table salt is sodium chloride, a combination of about 40% sodium and 60% chloride. All salt isn’t created equal: salt that’s more finely ground (like iodized table salt) contains more sodium than coarse sea salt, as the finely ground salts are denser.

• Food sources: Most of the sodium we consume comes from processed and packaged foods, not from adding table salt to foods. According to the Centers for Disease Control and Prevention, the top 10 sources of sodium in a standard American diet include: bread/rolls, pizza, sandwiches, cold cuts/deli meats, soups, burritos/tacos, savory snacks (like popcorn, chips, pretzels, crackers), chicken, cheese, and eggs
• AI: 1,500 mg daily, regardless of sex

Chloride: Chloride is another macromineral that functions as an electrolyte. It helps regulate cell health, maintains proper pH levels in the body, stimulates the stomach acid needed to digest food, and facilitates the flow of both oxygen and carbon dioxide in cells.

• Food sources: Salt (table, Kosher, and sea salts), seaweed, shrimp, processed foods, and high-sodium condiments (like ketchup, soy sauce, and Worcestershire sauce)
• AI: 3 grams (g) daily for those under 50, 2 g daily for those between 50 and 70, and 1.8 g daily for those over 70

Potassium: Just like sodium and chloride, potassium balances your electrolytes. It’s also essential for proper muscle and nerve function.

• Food sources: Dried fruits (apricots, raisins), avocado, bananas, chicken, salmon, tomatoes, potatoes, beans, lentils, winter squash
• AI: 2,300 mg daily for women 14-18, 2,600 mg for women 19+; 3,000 mg for men 14-18, 3,400 mg for men 19+

Sulfur: Your body uses sulfur to build and fix DNA, works to properly metabolize food, contributes to skin health, and protects the body from free radicals.

• Food sources: Allium vegetables (onions, garlic, leeks, chives, scallions), chickpeas, oats, whole grains, legumes, turkey, beef, fish, eggs, and cruciferous vegetables
• RDA: N/A*

*There is no RDA for sulfur because it is so abundant in the U.S. food supply.

Trace minerals

As the name suggests, trace minerals are only needed in very small quantities. They play a role in muscle health, nervous system regulation, and cell repair. Trace minerals include iron, manganese, copper, zinc, iodine, fluoride, and selenium.

Iron: The most common micronutrient deficiency in the world, with an estimated 1.76 billion people suffering from iron deficiency-related anemia as of 2019. Iron is key to healthy brain development and growth, and is a key component of hemoglobin, a type of protein in red blood cells that carries oxygen from your lungs to all parts of the body. Without enough iron in your system, there aren’t enough red blood cells to transport oxygen, leading to symptoms like fatigue.

• Food sources: Heme (animal products) - red meat, poultry, seafood; non-heme (plant foods) - whole grains, nuts, seeds, legumes, leafy greens
• RDA: 8 mg and 27 mg for men and women under 50, respectively; 27 mg during pregnancy; 11 mg and 15 mg for boys and girls under 19, respectively

Manganese: Manganese assists enzymes in breaking down macronutrients, building bones, and keeping the reproductive and immune systems working efficiently. Along with vitamin K, manganese aids in wound healing by helping to clot blood.

• Food sources: Shellfish, oatmeal, black tea, spinach, pineapple, chickpeas, lentils, brown rice, nuts, black pepper
• RDA: 3 mg and 1.3 mg for men and women, respectively. 2 mg is recommended during pregnancy, and 2.6 mg is recommended while breastfeeding

Copper: Not just for pennies! Copper works with enzymes in the body to produce energy, break down and absorb iron, and to build red blood cells, connective tissue, collagen, and neurotransmitters.

• Food sources: Organ meats, shellfish, nuts, seeds, fish, whole grains, and dark chocolate
• RDA: 900 mcg per day, regardless of sex; 1,300 mcg during pregnancy

Zinc: Although zinc is a trace mineral, it’s involved in over 100 chemical reactions throughout the body. It plays a key role in DNA creation, cell growth, protein building, healing damaged tissue, and supporting a healthy immune system. Zinc is also involved with your sense of taste and smell; zinc deficiency can result in hypogeusia, a dysfunction in your ability to taste.

• Food sources: Shellfish, pork, poultry, red meat, legumes, nuts, and seeds
• RDA: 11 mg and 8 mg for men and women, respectively

Iodine: Iodine is needed to make thyroid hormones, which help create proteins and regulate your metabolism. An iodine deficiency can lead to thyroid dysfunction and result in an under or over-active thyroid.

• Food sources: Iodized salt, dairy products, eggs, seaweed, beef liver, chicken, fish, and shellfish
• RDA: 150 mcg per day, regardless of sex; 220 mcg during pregnancy; 290 mcg while breastfeeding

Fluoride: Fluoride is heavily involved in supporting bone health – most notably your teeth – and preventing tooth decay.

• Food sources: Black tea, coffee, raisins, potatoes, canned shellfish, and fluorinated drinking water
• AI: 4 mg and 3 mg for men and women, respectively

Selenium: Selenium is an essential component in many enzymes and proteins, called selenoproteins. These selenoproteins help make DNA and protect against infection and cell damage. They are also involved in the metabolism and reproduction of thyroid hormones.

• Food sources: Brazil nuts, poultry, beans, lentils, whole-wheat bread, fortified cereals, and shellfish
• RDA: 55 mcg per day, regardless of sex

Micronutrients and a Balanced Diet

The best way to ensure you’re meeting the recommended daily allowance or adequate intake levels of micronutrients is through a balanced diet of nutrient-dense foods and beverages. These include things like plenty of vegetables, whole fruit and 100% fruit juice, legumes, whole grains, dairy, nuts, seeds, oils, as well as lean meat, poultry, and seafood.

Taking supplements like multivitamins can help you meet those minimums, but be careful to avoid toxic effects that are possible from too much of any one vitamin or mineral. Supplement toxicity can lead to vomiting, diarrhea, low blood pressure, liver failure, coma, or death. Before starting any new supplement, be sure to consult with your primary care physician.

Are You Passionate About Nutrition?

By understanding more about the foods that nourish you, you can make educated decisions to find a way of eating and living that meets your bio-individual needs. The Institute for Integrative Nutrition’s goal is to empower you with knowledge and science-based evidence of potential benefits of a certain way of eating or living. It’s up to you as a bio-individual to review the available research and determine which new food groups or supplements fit best into your life.