Micronutrients are one of the major groups of nutrients your body needs. They include vitamins and minerals.
Vitamins are necessary for energy production, immune function, blood clotting, and other functions. Meanwhile, minerals play an important role in growth, bone health, fluid balance, and several other processes.
This article provides a detailed overview of micronutrients, their functions, and implications of excess consumption or deficiency.
What are micronutrients?
The term micronutrients is used to describe vitamins and minerals in general.
Macronutrients, on the other hand, include proteins, fats, and carbohydrates.
Your body needs smaller amounts of micronutrients relative to macronutrients. That’s why they’re labeled “micro.”
Humans must obtain micronutrients from food since your body cannot produce vitamins and minerals — for the most part. That’s why they’re also referred to as essential nutrients.
Vitamins are organic compounds made by plants and animals which can be broken down by heat, acid, or air. On the other hand, minerals are inorganic, exist in soil or water, and cannot be broken down.
When you eat, you consume the vitamins that plants and animals created or the minerals they absorbed.
The micronutrient content of each food is different, so it’s best to eat a variety of foods to get enough vitamins and minerals.
An adequate intake of all micronutrients is necessary for optimal health, as each vitamin and mineral has a specific role in your body.
Vitamins and minerals are vital for growth, immune function, brain development, and many other important functions.
Depending on their function, certain micronutrients also play a role in preventing and fighting disease.
Summary: Micronutrients include vitamins and minerals. They’re critical for several important functions in your body and must be consumed from food.
Types and functions of micronutrients
Vitamins and minerals can be divided into four categories: water-soluble vitamins, fat-soluble vitamins, macrominerals, and trace minerals.
Regardless of type, vitamins and minerals are absorbed in similar ways in your body and interact in many processes.
Water-soluble vitamins
Most vitamins dissolve in water and are therefore known as water-soluble. They’re not easily stored in your body and get flushed out with urine when consumed in excess.
While each water-soluble vitamin has a unique role, its functions are related.
For example, most B vitamins act as coenzymes that help trigger important chemical reactions. A lot of these reactions are necessary for energy production.
The water-soluble vitamins — with some of their functions — are:
- Vitamin B1 (thiamine): Helps convert nutrients into energy.
- Vitamin B2 (riboflavin): Necessary for energy production, cell function, and fat metabolism.
- Vitamin B3 (niacin): Drives the production of energy from food.
- Vitamin B5 (pantothenic acid): Necessary for fatty acid synthesis.
- Vitamin B6 (pyridoxine): Helps your body release sugar from stored carbohydrates for energy and create red blood cells.
- Vitamin B7 (biotin): Plays a role in the metabolism of fatty acids, amino acids, and glucose.
- Vitamin B9 (folate): Important for proper cell division.
- Vitamin B12 (cobalamin): Necessary for red blood cell formation and proper nervous system and brain function.
- Vitamin C (ascorbic acid): Required for the creation of neurotransmitters and collagen, the main protein in your skin.
As you can see, water-soluble vitamins play an important role in producing energy but also have several other functions.
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Since these vitamins are not stored in your body, it’s important to get enough of them from food.
Sources and recommended dietary allowances or adequate intakes of water-soluble vitamins are:
- Vitamin B1 (thiamine) sources: Whole grains, meat, fish - (1.1–1.2 mg)
- Vitamin B2 (riboflavin) sources: Organ meats, eggs, milk - (1.1–1.3 mg)
- Vitamin B3 (niacin) sources: Meat, salmon, leafy greens, beans - (14–16 mg)
- Vitamin B5 (pantothenic acid) sources: Organ meats, mushrooms, tuna, avocado - (5 mg)
- Vitamin B6 (pyridoxine) sources: Fish, milk, carrots, potatoes - (1.3 mg)
- Vitamin B7 (biotin) sources: Eggs, almonds, spinach, sweet potatoes - (30 mcg)
- Vitamin B9 (folate) sources: Beef, liver, black-eyed peas, spinach, asparagus - (400 mg)
- Vitamin B12 (cobalamin) sources: Clams, fish, meat - (2.4 mcg)
- Vitamin C (ascorbic acid) sources: Citrus fruits, bell peppers, Brussels sprouts - (75–90 mg)
Fat-soluble vitamins
Fat-soluble vitamins do not dissolve in water.
They’re best absorbed when consumed alongside a source of fat. After consumption, fat-soluble vitamins are stored in your liver and fatty tissues for future use.
The names and functions of fat-soluble vitamins are:
- Vitamin A: Necessary for proper vision and organ function.
- Vitamin D: Promotes proper immune function and assists in calcium absorption and bone growth.
- Vitamin E: Assists immune function and acts as an antioxidant that protects cells from damage.
- Vitamin K: Required for blood clotting and proper bone development.
Sources and recommended intakes of fat-soluble vitamins are:
- Vitamin A sources: Retinol (liver, dairy, fish), carotenoids (sweet potatoes, carrots, spinach) - (700–900 mcg)
- Vitamin D sources: Sunlight, fish oil, milk - (600–800 IU)
- Vitamin E sources: Sunflower seeds, wheat germ, almonds - (15 mg)
- Vitamin K sources: Leafy greens, soybeans, pumpkin - (90–120 mcg)
Macrominerals
Macrominerals are needed in larger amounts than trace minerals in order to perform their specific roles in your body.
Suggested read: B-complex vitamins: Benefits, side effects and dosage
The macrominerals and some of their functions are:
- Calcium: Necessary for proper structure and function of bones and teeth. Assists in muscle function and blood vessel contraction.
- Phosphorus: Part of bone and cell membrane structure.
- Magnesium: Assists with over 300 enzyme reactions, including regulation of blood pressure.
- Sodium: Electrolyte that aids fluid balance and maintenance of blood pressure.
- Chloride: Often found in combination with sodium. Helps maintain fluid balance and is used to make digestive juices.
- Potassium: Electrolyte that maintains fluid status in cells and helps with nerve transmission and muscle function.
- Sulfur: Part of every living tissue and contained in the amino acids methionine and cysteine.
Sources and recommended intakes of the macrominerals are:
- Calcium sources: Milk products, leafy greens, broccoli - (2,000–2,500 mg)
- Phosphorus sources: Salmon, yogurt, turkey - (700 mg)
- Magnesium sources: Almonds, cashews, black beans - (310–420 mg)
- Sodium sources: Salt, processed foods, canned soup - (2,300 mg)
- Chloride sources: Seaweed, salt, celery - (1,800–2,300 mg)
- Potassium sources: Lentils, acorn squash, bananas - (4,700 mg)
- Sulfur sources: Garlic, onions, Brussels sprouts, eggs, mineral water
Trace minerals
Trace minerals are needed in smaller amounts than macrominerals but still enable important functions in your body.
The trace minerals and some of their functions are:
- Iron: Helps provide oxygen to muscles and assists in the creation of certain hormones.
- Manganese: Assists in carbohydrate, amino acid, and cholesterol metabolism.
- Copper: Required for connective tissue formation, as well as normal brain and nervous system function.
- Zinc: Necessary for normal growth, immune function and wound healing.
- Iodine: Assists in thyroid regulation.
- Fluoride: Necessary for the development of bones and teeth.
- Selenium: Important for thyroid health, reproduction, and defense against oxidative damage.
Sources and recommended intakes of trace minerals are:
- Iron sources: Oysters, white beans, spinach - (8–18 mg)
- Manganese sources: Pineapple, pecans, peanuts - (1.8–2.3 mg)
- Copper sources: Liver, crabs, cashews - (900 mcg)
- Zinc sources: Oysters, crab, chickpeas - (8–11 mg)
- Iodine sources: Seaweed, cod, yogurt - (150 mcg)
- Fluoride sources: Fruit juice, water, crab - (3–4 mg)
- Selenium sources: Brazil nuts, sardines, ham - (55 mcg)
Summary: Micronutrients can be divided into four groups — water-soluble vitamins, fat-soluble vitamins, macrominerals, and trace minerals. The functions, food sources, and recommended intakes of each vitamin and mineral vary.
Health benefits of micronutrients
All micronutrients are extremely important for the proper functioning of your body.
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Consuming an adequate amount of the different vitamins and minerals is key to optimal health and may even help fight disease.
This is because micronutrients are part of nearly every process in your body. Moreover, certain vitamins and minerals can act as antioxidants.
Antioxidants may protect against cell damage that has been associated with certain diseases, including cancer, Alzheimer’s, and heart disease.
For example, research has linked an adequate dietary intake of vitamins A and C with a lower risk of some types of cancer.
Getting enough of some vitamins may also help prevent Alzheimer’s disease. A review of seven studies found that adequate dietary intake of vitamins E, C, and A is associated with a 24%, 17%, and 12% reduced risk of developing Alzheimer’s, respectively.
Certain minerals may also play a role in preventing and fighting disease.
Research has linked low blood levels of selenium to a higher risk of heart disease. A review of observational studies found that the risk of heart disease decreased by 24% when blood concentrations of selenium increased by 50%.
Additionally, a review of 22 studies noticed that adequate calcium intake decreases the risk of death from heart disease and all other causes.
These studies suggest that consuming enough of all micronutrients — especially those with antioxidant properties — provides ample health benefits.
However, it’s unclear whether consuming more than the recommended amounts of certain micronutrients — either from foods or supplements — offers additional benefits.
Summary: Micronutrients are part of nearly every process in your body. Some even act as antioxidants. Due to their important role in health, they may protect against diseases.
Micronutrient deficiencies and toxicities
Micronutrients are needed in specific amounts to perform their unique functions in your body.
Getting too much or too little of a vitamin or mineral can lead to negative side effects.
Deficiencies
Most healthy adults can get an adequate amount of micronutrients from a balanced diet, but there are some common nutrient deficiencies that affect certain populations.
These include:
- Vitamin D: Approximately 77% of Americans are deficient in vitamin D, mostly due to lack of sun exposure.
- Vitamin B12: Vegans and vegetarians may develop vitamin B12 deficiency from refraining from animal products. Elderly individuals are also at risk due to decreased absorption with age.
- Vitamin A: The diets of women and children in developing countries often lack adequate vitamin A.
- Iron: Deficiency of this mineral is common among preschool children, menstruating women, and vegans.
- Calcium: Close to 22% and 10% of men and women over 50, respectively, don’t get enough calcium.
The signs, symptoms, and long-term effects of these deficiencies depend on each nutrient but can be detrimental to the proper functioning of your body and optimal health.
Toxicities
Micronutrient toxicities are less common than deficiencies.
They are most likely to occur with large doses of the fat-soluble vitamins A, D, E, and K since these nutrients can be stored in your liver and fatty tissues. They cannot be excreted from your body like water-soluble vitamins.
Micronutrient toxicity usually develops from supplementing with excess amounts — rarely from food sources. Signs and symptoms of toxicity vary depending on the nutrient.
It’s important to note that excessive consumption of certain nutrients can still be dangerous even if it does not lead to overt toxicity symptoms.
One study examined over 18,000 people with a high risk of lung cancer due to past smoking or asbestos exposure. The intervention group received two types of vitamin A — 30 mg of beta-carotene and 25,000 IU of retinyl palmitate a day.
The trial was halted ahead of schedule when the intervention group showed 28% more cases of lung cancer and a 17% greater incidence of death over 11 years compared to the control group.
Micronutrient supplements
The safest and most effective way to get adequate vitamin and mineral intake appear to be from food sources.
More research is needed to fully understand the long-term effects of toxicities and supplements.
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However, people at risk of specific nutrient deficiencies may benefit from taking supplements under the supervision of a doctor.
If you’re interested in taking micronutrient supplements, look for products certified by a third party. Unless otherwise directed by a healthcare provider, be sure to avoid products that contain “super” or “mega” doses of any nutrient.
Summary: Since your body requires micronutrients in specific amounts, deficiencies and surpluses of any one nutrient may lead to negative issues. If you’re at risk of a specific deficiency, talk to your doctor before starting supplements.
Summary
The term micronutrients refers to vitamins and minerals, which can be divided into macro minerals, trace minerals, and water- and fat-soluble vitamins.
Vitamins are needed for energy production, immune function, blood clotting, and other functions while minerals benefit growth, bone health, fluid balance, and other processes.
To get an adequate amount of micronutrients, aim for a balanced diet containing a variety of foods.
