Essential Micronutrients in Food

Micronutrients, also known as vitamins and minerals, are vital to overall health and well-being. Micronutrients are important for functions such as blood-clotting, brain development, immune system function, energy production, and bone health. They play critical roles in disease prevention.

A few micronutrients are vitamins A, C, and D and the minerals iron, potassium, and calcium. This article discusses micronutrients in food, the need for micronutrients, symptoms of micronutrient deficiency, and how many micronutrients are needed daily.

Examples of Micronutrients in Food

Aside from vitamin D, your body cannot make micronutrients, so they must be obtained from the diet. Each food group provides several different vitamins and minerals. Eating a variety of foods is the best way to get all the micronutrients you need.

Micronutrients and select food sources of each are as follows.

Fat-Soluble Vitamins

Sources of fat-soluble vitamins include:

• Vitamin A: Beef liver, fish, eggs, fortified dairy products, sweet potatoes, carrots, cantaloupe
• Vitamin D: Fatty fish, such as trout, tuna, and salmon, fish liver oils, egg yolks, fortified milk, mushrooms, especially those exposed to ultraviolet (UV) light
• Vitamin E: Nuts (such as almonds, peanuts, and hazelnuts), seeds, vegetable oils, spinach, broccoli
• Vitamin K: Leafy green vegetables (such as collard greens, spinach, kale, and broccoli), vegetable oils, blueberries, and pomegranate juice

Water-Soluble Vitamins

Sources of water-soluble vitamins include:

• Vitamin C (ascorbic acid): Citrus fruits, kiwi, bell peppers, broccoli, strawberries, tomatoes
• Vitamin B1 (thiamine): Whole grains, fortified cereals, pork, beef, trout, tuna, black beans
• Vitamin B2 (riboflavin): Eggs, beef liver, milk, yogurt, cheese, fortified cereals, almonds, clams
• Vitamin B3 (niacin): Chicken, turkey, beef, pork, salmon, tuna, peanuts, potatoes, rice
• Vitamin B5 (pantothenic acid): Beef, chicken, organ meats, whole grains, shiitake mushrooms, sunflower seeds, avocado
• Vitamin B6 (pyridoxine): Chickpeas, beef liver, turkey, tuna, salmon, chicken, fortified cereals, potatoes, banana
• Vitamin B7 (biotin): Organ meats, eggs, salmon, pork, beef, sunflower seeds, almonds, sweet potato
• Vitamin B9 (folate): Beef liver, spinach, fortified cereals and grains, spinach, asparagus, brussels sprouts, beans, nuts
• Vitamin B12 (cobalamin): Beef liver, nutritional yeast, fatty fish (salmon, tuna), clams, beef, dairy products, eggs

Macrominerals

Sources of macrominerals include:

• Calcium: Dairy products, fortified orange juice, canned sardines and salmon with bones, tofu, soybeans, spinach, kale
• Magnesium: Spinach, pumpkin seeds, chia seeds, almonds, cashews, peanuts, soy milk, black beans, potatoes, brown rice
• Phosphorus: Dairy products, salmon, chicken, beef, scallops, lentils, potatoes, kidney beans
• Potassium: Dried apricots, lentils, prunes, raisins, potatoes, oranges, bananas, acorn squash
• Sodium: Salt, prepared and processed foods such as breads, deli meats, frozen meals, canned foods, chips, salted popcorn
• Sulfur: Broccoli cabbage, cauliflower, onion, garlic, dairy products, fish, legumes, nuts, meats, raspberries, wheat germ

Trace Minerals

Sources of trace minerals include:

• Copper: Shellfish, seeds, nuts, organ meats, whole grains, chocolate, potatoes, mushrooms
• Chromium: Beef, pork, turkey, brewer’s yeast, grape and orange juice, grain products
• Fluoride: Brewed tea and coffee, shrimp, water with added fluoride
• Iodine: Iodized salt, seaweed, fish, eggs, cheese, foods made with iodized salt
• Iron: Beef, pork, turkey, fish, fortified cereals and grains, spinach, tofu, lentils, beans, dark chocolate
• Manganese: Whole grains, clams, oysters, mussels, nuts, soybeans, legumes, rice, coffee, tea, leafy green vegetables
• Molybdenum: Legumes, whole grains, nuts, beef liver, milk, yogurt
• Selenium: Brazil nuts, fish, shrimp, organ meats, fortified cereals, beef, turkey, chicken, dairy products
• Zinc: Beef, oysters, blue crab, fortified cereals and grains, pumpkin seeds, turkey, cheese, shrimp

Why Do People Need Micronutrients?

Micronutrients play crucial roles in growth and development from the earliest stages of human development and on—from fetuses to infants, children, and adults. They are required for optimal nutrition, and they support many body structures and processes.

For example, folate (vitamin B9) helps prevent some congenital (present at birth) conditions, make DNA and other genetic materials, and is needed for cell division. Calcium strengthens bones and teeth and supports the body’s circulatory system, nerve function, hormonal secretion, and blood clotting. Iodine is important for early cognitive development and thyroid health.

Some micronutrients, including vitamins A, C, and E, copper, zinc, and selenium, act as antioxidants, which help protect the body against oxidative stress due to excess free radicals (byproducts of turning food into energy). Free radicals can damage organs, tissues, and genetic materials.

Each micronutrient has different roles in keeping the body growing and functioning properly. Deficiency can throw off the balance and lead to a host of problems. 

Symptoms of Micronutrient Deficiency 

Micronutrient deficiencies can cause visible and life-threatening health conditions. But there may also be less noticeable symptoms, including decreased energy, mental sharpness, and overall day-to-day functioning. These harder-to-spot symptoms can lead to trouble learning, decreased work productivity, and increased risk of infection and other diseases.

Some micronutrient deficiencies are prevalent around the globe, especially in developing countries. According to the Centers for Disease Control and Prevention (CDC), at least half of children worldwide younger than 5 years of age are affected by micronutrient deficiencies.

Below are six common worldwide micronutrient deficiencies and their associated symptoms:

• Iron: Fatigue, pale skin, cold hands and feet, dizziness or light-headedness
• Vitamin A: Night blindness, dry eye, decreased ability to fight infections, impaired vision, stunted growth
• Vitamin D: Muscle aches or spasms, weakness, bone pain, fatigue, mood changes
• Zinc: Diarrhea, hair loss (alopecia), delayed growth, frequent infections, loss of appetite, reproductive problems, decreased sense of taste and smell
• Iodine: Lump on your neck (goiter), neck pressure, difficulty swallowing, intellectual disabilities or growth, hearing and speech problems in infants born to a pregnant person who was iodine deficient during pregnancy, feeling cold, fatigue, forgetfulness, depression, or constipation
• Folate: Weakness, fatigue, difficulty concentrating, irritability, headache, heart palpitations, and shortness of breath, and neural tube defects (conditions affecting the spine, spinal cord, and brain that are present at birth) in babies caused by insufficient folate levels during the early stages of pregnancy 

How Many Micronutrients Do You Need Daily?

It’s important to eat a balanced diet with a variety of foods daily to ensure you are getting the vitamins and minerals your body needs to properly function. Below are the amounts of micronutrients needed per day for adults aged 19 or older, based on the recommended dietary allowances (RDAs) or adequate intakes (AIs).

Fat Soluble Vitamins

Recommended amounts:

• Vitamin A: 700 to 1,300 mcg RAE (retinol activity equivalents)
• Vitamin D: 15 to 20 mcg
• Vitamin E: 15 to 19 mg
• Vitamin K: 90 to 120 mcg

Water-Soluble Vitamins

Recommended amounts:

• Vitamin C (ascorbic acid): 75 to 120 mg
• Vitamin B1 (thiamin): 1.1 to 1.4 mg
• Vitamin B2 (riboflavin): 1.1 to 1.6 mg
• Vitamin B3 (niacin): 14 to 18 mg niacin equivalent (NE)
• Vitamin B5 (pantothenic acid): 5 to 7 mg
• Vitamin B6 (pyridoxine): 1.3 to 2.0 mg
• Vitamin B7 (biotin): 30 to 35 mcg
• Vitamin B9 (folate): 400 to 600 mcg dietary folate equivalents (DFE)
• Vitamin B12 (cobalamin): 2.4 to 2.8 mcg

Macrominerals

Recommended amounts:

• Calcium: 1,000 to 1,200 mg
• Magnesium: 310 to 420 mg
• Phosphorus: 700 mg
• Potassium: 2,600 to 3,400 mg

Trace Minerals

Recommended amounts:

• Copper: 900 to 1,300 mcg
• Chromium: 20 to 45 mcg
• Fluoride: 3 to 4 mg
• Iodine: 150 to 290 mcg 
• Iron: 8 to 27 mg
• Manganese: 1.8 to 2.6 mg
• Molybdenum: 45 to 50 mcg
• Selenium: 55 to 70 mcg
• Zinc: 8 to 12 mg

Summary

Micronutrients are vitamins and minerals required by the body for many processes, growth, and functioning. They are found in every food group, including fruits, vegetables, grains, dairy, proteins, and fats. Eating a variety of foods each day is the best way to get all the micronutrients you need.

Micronutrients are required for optimal nutrition and immune function, and support many body structures and processes, as well as help protect against diseases and other health conditions.

Symptoms of a deficiency depend on the vitamin or mineral that is lacking in the body and can range from mild to serious. Amounts of micronutrients needed daily also vary and are specific to each vitamin or mineral.