What Are Micronutrients?
Micronutrients: Types, Functions, and Sources
You’ve likely heard of macronutrients; the carbohydrates, proteins, and fats found in food, but what about micronutrients? From vitamins to minerals and everything in between, here are is a breakdown of micronutrients; the different types, functions, benefits, and sources.
What Are Micronutrients?
All food contains macronutrients and micronutrients; they are the primary elements of nutrition and our bodies require them every day. The term micronutrient refers specifically to vitamins and minerals; a smaller category of nutrients that do not contain calories and are required in smaller amounts than macronutrients. Vitamins and minerals are vital to healthy development, disease prevention, and overall wellbeing.
Micronutrients vs. Macronutrients
Nutrients can be divided into two primary categories: macronutrients and micronutrients. Macronutrients (carbohydrates, protein, and fat) are the primary nutrients in our diet and supply the body with energy via calories, while micronutrients (vitamins and minerals) are essential nutrients that play a wide variety of roles in metabolic processes in the human body. Micronutrients are equally important as macronutrients but are required in much smaller amounts, hence the terms micro (small) and macro (large) nutrients.
Types of Micronutrients
There are two primary types of micronutrients; vitamins and minerals, each of which includes various formats.
Vitamins are organic substances produced by plants and animals and are required for cell function, growth, metabolism, and development. There are two categories of vitamins: fat-soluble and water-soluble.
Fat-Soluble Vitamins: Fat-soluble vitamins include vitamin A, D, E, and K. These vitamins are typically present in sources of fat and more easily digested, assimilated, and absorbed in the presence of fat. Fat-soluble vitamins are stored in the liver and fatty tissues for future use and the reserves of these vitamins will remain in the body for extended periods of time, days, sometimes months.
Water-Soluble Vitamins: Water-soluble vitamins include the B vitamins and vitamin C. These vitamins are called water-soluble vitamins because they dissolved in water and, therefore, do not stay or cannot be stored by the body. Because they are excreted through urine when consumed in excess, regular consumption of water-soluble vitamins is vital.
Minerals are chemical elements found in soil and water and are not produced by living organisms. Unlike vitamins, minerals are not easily destroyed by the elements and are transported by soil and water into plants and animals. Minerals are also classified by macro and micro terms: macrominerals are required in amounts greater than 100 mg per day, while microminerals are those nutrients required in amounts less than 100 mg per day. (1)
Macrominerals: Macrominerals include calcium, phosphorus, magnesium, sodium, chloride, potassium, and sulfur. These minerals are required in larger amounts and perform a number of very specific roles in the body.
Microminerals: Also known as trace minerals, microminerals include iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium, and molybdenum. Although still essential to the human body, microminerals are required in smaller amounts than macrominerals.
Functions and Benefits of Micronutrients
Because the human body cannot obtain or create micronutrients on its own, they must be obtained through our diet. Each micronutrient plays a different role in the human body, all of which are important and essential. Consuming adequate amounts of vitamins and minerals is vital for optimal health and preventing disease. Deficiencies in vitamins and minerals have been linked to a number of chronic health conditions. (2)
Sources of Micronutrients
Fortunately, vitamins and minerals can be found in a wide variety of food sources and adequate consumption of whole food and macronutrients can help to support overall micronutrient intake. Primary food sources of micronutrients include (3)(4).
Vitamin A: Retinol from animal sources: fortified milk, cheese, cream, butter, fortified margarine, eggs, liver; Beta-carotene from plant sources: leafy dark green vegetables, dark orange fruits (apricots, cantaloupe), and vegetables (carrots, winter squash, sweet potatoes, pumpkin)
Vitamin D: Egg yolk, liver, fatty fish, milk, sunlight
Vitamin E: Polyunsaturated plant oils (soybean, corn, cottonseed, safflower); leafy green vegetables, wheat germ, whole-grain products, liver, egg yolks, nuts, seeds
Vitamin K: Leafy green vegetables such as kale, collard greens, and spinach, green vegetables such as broccoli, brussel sprouts, and asparagus; also produced in the intestinal tract by bacteria
B Vitamins: Meat, organ meats, fish, eggs, milk, whole grains, generally widespread in foods
Calcium: Milk and milk products; canned fish with bones (salmon, sardines), fortified tofu and fortified soy milk, greens (broccoli, mustard greens), legumes
Phosphorus: Meat, fish, poultry, eggs, milk
Magnesium: Nuts, seeds, legumes; leafy, green vegetables, seafood, dark chocolate, artichokes
Sodium: Salt, soy sauce, small amounts in milk, breads, vegetables, unprocessed meats
Chloride: Seaweed, salt, celery, soy sauce
Potassium: Meats, milk, fresh fruits and vegetables, whole grains, legumes
Sulfur: Occurs in foods as part of protein: meats, poultry, fish, eggs, milk, legumes, nuts
Iron: Organ meats, red meats, fish, poultry, shellfish (especially clams), egg yolks, legumes, dark leafy greens
Zinc: Meats, fish, poultry, leavened whole grains, vegetables
Iodine: Seafood, foods grown in iodine-rich soil, iodized salt, bread, dairy products
Selenium: Meats, seafood, grains
Copper: Legumes, nuts, seeds, whole grains, organ meats, drinking water
Manganese: Widespread in foods, especially plant foods, almonds, cashews, black beans
Fluoride: Fish, crab, tap water, fruit juice, tea
Chromium: Liver, brewer’s yeast, whole grains, nuts, cheeses
Molybdenum: Legumes, grains, leafy greens, milk, liver
The safest and most natural way to get micronutrients is through food sources, however, some individuals, especially those with nutrient deficiencies or underlying health conditions, can benefit from micronutrient supplementation. The supplementation of specific dosages of vitamins and minerals can help to support specific health conditions, stages of life (i.e. pregnancy or menopause), or personal health goals. If you are concerned you are not getting adequate nutrients through food, it is best to speak with a doctor, dietician, or registered health professional that specialized in this area.
The Bottom Line
The term micronutrient refers to a category of nutrients and includes vitamins and minerals, which are essential for overall health. Vitamins include fat-soluble and water-soluble vitamins, while minerals include macrominerals and trace minerals, all of which can be found in food and supplement forms. Generally speaking, adequate consumption of whole foods and a well-balanced diet of carbohydrates, protein, and fat can help to are adequate consumption of micronutrients, however, in some cases, individuals can benefit from micronutrient supplements.