Our macronutrients include protein, carbohydrates and fat and provide us with the calories we need to function and survive. However, our macronutrients are the supply chain for all of our micronutrients.
- Macro = Large
- Micro = Small
Micronutrients are substances which are required by the body in small quantities to ensure normal metabolism, growth and physical well-being.
In this article I will provide a detailed overview of micronutrients, their functions and consequences of deficiencies or excess consumption.
What Are Micronutrients?
The term micronutrient is used to describe vitamins and minerals your body needs to thrive.
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 substances that exist in soil or water and cannot be broken down.
Vitamins are necessary for energy production, immune function, blood clotting and other functions while minerals play an important role in growth, bone health, blood clotting, muscle contraction, fluid balance and several other processes. (1, 2, 3)
Humans must obtain micronutrients from food since your body cannot produce vitamins and minerals internally. That’s why they’re also referred to as essential nutrients.
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. (4, 5, 6)
Micronutrients Types and Functions
Vitamins and minerals can be divided into four categories:
- Water-soluble vitamins
- Fat-soluble vitamins
- Macro-minerals
- Trace minerals
Regardless of type, vitamins and minerals are absorbed in similar ways in your body and interact in numerous important 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, their functions are related.
For example, most B vitamins act as coenzymes that help trigger important chemical reactions. And many of these reactions are necessary for energy production.
Here is a list of water-soluble vitamins along with some of their main functions:
- Vitamin B1 (thiamine): Helps convert nutrients into energy. (7)
- Vitamin B2 (riboflavin): Necessary for energy production, cell function and fat metabolism. (8)
- Vitamin B3 (niacin): Drives the production of energy from food. (9, 10)
- Vitamin B5 (pantothenic acid): Necessary for fatty acid synthesis. (11)
- Vitamin B6 (pyridoxine): Helps your body release sugar from stored carbohydrates for energy and create red blood cells. (12)
- Vitamin B7 (biotin): Plays a role in the metabolism of fatty acids, amino acids and glucose. (13)
- Vitamin B9 (folate): Important for proper cell division. (14)
- Vitamin B12 (cobalamin): Necessary for red blood cell formation and proper nervous system and brain function. (15)
- Vitamin C (ascorbic acid): Required for the creation of neurotransmitters and collagen, the main protein in your skin. (16)
As you can see, water-soluble vitamins play a critical role in producing energy but also have several other important functions as well.
Since these vitamins are not stored in your body, it’s important to get enough of them from food.
Sources and Recommended Dietary Allowances (RDAs) or Adequate Intakes (AIs) of water-soluble vitamins are:
| Nutrient | Sources | RDA or AI (adults > 19 years) |
| Vitamin B1 (thiamine) | Whole grains, meat, fish | 1.1–1.2 mg |
| Vitamin B2 (riboflavin) | Organ meats, eggs, milk | 1.1–1.3 mg |
| Vitamin B3 (niacin) | Meat, salmon, leafy greens, beans | 14–16 mg |
| Vitamin B5 (pantothenic acid) | Organ meats, mushrooms, tuna, avocado | 5 mg |
| Vitamin B6 (pyridoxine) | Fish, milk, carrots, potatoes | 1.3 mg |
| Vitamin B7 (biotin) | Eggs, almonds, spinach, sweet potatoes | 30 mcg |
| Vitamin B9 (folate) | Beef, liver, black-eyed peas, spinach, asparagus | 400 mg |
| Vitamin B12 (cobalamin) | Clams, fish, meat | 2.4 mcg |
| Vitamin C (ascorbic acid) | Citrus fruits, bell peppers, Brussels sprouts | 75–90 mg |
Fat-Soluble Vitamins
Fat-soluble vitamins do not dissolve in water and therefore are best absorbed when consumed alongside a source of dietary fat.
After consuming fat-soluble vitamins, they are transported and stored in your liver and adipose tissues (fat) for future use.
Here is a list of fat-soluble vitamins along with some of their main functions:
- Vitamin A: Necessary for proper vision and organ function. (17)
- Vitamin D: Promotes proper immune function and assists in calcium absorption and bone growth. (18)
- Vitamin E: Assists immune function and acts as an antioxidant that protects cells from damage. (19)
- Vitamin K: Required for blood clotting and proper bone development. (20)
Sources and recommended intakes of fat-soluble vitamins are:
| Nutrient | Sources | RDA or AI (adults > 19 years) |
| Vitamin A | Retinol (liver, dairy, fish), carotenoids (sweet potatoes, carrots, spinach) | 700–900 mcg |
| Vitamin D | Sunlight, fish oil, milk | 600–800 IU |
| Vitamin E | Sunflower seeds, wheat germ, almonds | 15 mg |
| Vitamin K | 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.
Here is a list of macrominerals along with some of their main functions:
- Calcium: Necessary for proper structure and function of bones and teeth. Assists in muscle function and blood vessel contraction. (21)
- Phosphorus: Part of bone and cell membrane structure. (22)
- Magnesium: Assists with over 300 enzyme reactions, including regulation of blood pressure. (23)
- Sodium: Electrolyte that aids fluid balance and maintenance of blood pressure. (24)
- Chloride: Often found in combination with sodium. Helps maintain fluid balance and is used to make digestive juices. (25)
- Potassium: Electrolyte that maintains fluid status in cells and helps with nerve transmission and muscle function. (26)
- Sulfur: Part of every living tissue and contained in the amino acids methionine and cysteine. (27)
Sources and recommended intakes of recommended intake of macrominerals:
| Nutrient | Sources | RDA or AI (adults > 19 years) |
| Calcium | Milk products, leafy greens, broccoli | 2,000–2,500 mg |
| Phosphorus | Salmon, yogurt, turkey | 700 mg |
| Magnesium | Almonds, cashews, black beans | 310–420 mg |
| Sodium | Salt, processed foods, canned soup | 2,300 mg |
| Chloride | Seaweed, salt, celery | 1,800–2,300 mg |
| Potassium | Lentils, acorn squash, bananas | 4,700 mg |
| Sulfur | Garlic, onions, Brussels sprouts, eggs, mineral water | None established |
Trace Minerals
Trace minerals are needed in smaller amounts than macrominerals but still enable important functions in your body.
Here is a list of trace minerals along with some of their main functions:
- Iron: Helps provide oxygen to muscles and assists in the creation of certain hormones. (28)
- Manganese: Assists in carbohydrate, amino acid and cholesterol metabolism. (29)
- Copper: Required for connective tissue formation, as well as normal brain and nervous system function. (30)
- Zinc: Necessary for normal growth, immune function and wound healing (31).
- Iodine: Assists in thyroid regulation. (32)
- Fluoride: Necessary for the development of bones and teeth. (33)
- Selenium: Important for thyroid health, reproduction and defense against oxidative damage. (34)
Sources and recommended intakes of trace minerals are:
| Nutrient | Sources | RDA or AI (adults > 19 years) |
| Iron | Oysters, white beans, spinach | 8–18 mg |
| Manganese | Pineapple, pecans, peanuts | 1.8–2.3 mg |
| Copper | Liver, crabs, cashews | 900 mcg |
| Zinc | Oysters, crab, chickpeas | 8–11 mg |
| Iodine | Seaweed, cod, yogurt | 150 mcg |
| Fluoride | Fruit juice, water, crab | 3–4 mg |
| Selenium | Brazil nuts, sardines, ham | 55 mcg |
Micronutrients Health Benefits
All micronutrients are extremely important for the proper functioning of your body.
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. (35, 36, 37)
For example, research has linked an adequate dietary intake of vitamin A and C with a lower risk of certain types of cancer. (38, 39)
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 up to a 24 percent reduced risk of developing Alzheimer’s. (40, 41)
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 as much as 24 percent when blood concentrations of selenium increased by 50 percent. (42)
Additionally, a review of 22 studies observed that adequate calcium intake decreases the risk of death from heart disease. (43)
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 any additional benefit. (44, 45)
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.
Micronutrient Deficiencies
Most healthy adults can get an adequate supply of micronutrients from a balanced diet, but there are some common nutrient deficiencies that affect certain populations.
These include:
- Vitamin D: Approximately 77 percent of Americans are deficient in vitamin D, mostly due to lack of sun exposure. (46)
- 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. (47, 48)
- Vitamin A: The diets of women and children in developing countries often lack adequate vitamin A. (49)
- Iron: Deficiency of this mineral is common among preschool children, menstruating women and vegans. (50, 51)
- Calcium: Nearly 22 percent of men and women over the age of 50 don’t get enough calcium. (52)
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.
Micronutrient 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.
A micronutrient toxicity usually develops from over supplementing with excess amounts. And signs and symptoms of toxicity vary depending on the nutrient being supplemented.
It’s important to note that excessive consumption of certain nutrients can still be dangerous even if it does not lead to over toxicity symptoms.
Micronutrient Supplements
The safest and most effective way to get adequate vitamin and mineral intake appears to be from whole food sources. (53, 54)
More research is needed to fully understand the long-term effects of toxicities and supplements.
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 professional, be sure to avoid products that contain “super” or “mega” doses of any nutrient.
The Bottom Line:
The term micronutrient 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, immunity, blood clotting and other important functions while minerals benefit growth, bone health, fluid balance and other vital processes.
To get an adequate supply of micronutrients, aim for a balanced diet containing a variety of whole, unprocessed foods.
