What are micronutrients?

Micronutrients are defined as vitamins and minerals and have numerous essential functions.

What are vitamins?

Vitamins are essential nutrients needed in small amounts and are involved in many complex bodily systems. There are two types of vitamins: fat-soluble and water-soluble.

Fat-soluble vitamins

Fat-soluble vitamins tend to be found in fatty foods such as animal fats, vegetable oils, dairy foods and oily fish.

Whilst the body needs these vitamins daily, if they are not used immediately or consumed in large doses they are stored in the liver and fatty tissues, and these stores can build up. If these stores become excessive, fat-soluble vitamins can be harmful.

Water-soluble vitamins

Water-soluble vitamins, however, are not stored in the body and so need to be consumed daily. Unlike fat-soluble vitamins excess levels of water-soluble vitamins are expelled through urination. Because the body doesn’t store water-soluble vitamins, generally these vitamins aren’t harmful if taken in large doses.

Water-soluble vitamins are found in a variety of fruit, vegetables and grains but are easily destroyed by heat or merely by being exposed to the air.

What are minerals?

Minerals, whilst needed in small amounts, are vital nutrients involved in many complex bodily systems. They are divided into essential minerals and trace minerals.

The principal role of minerals in the body include:

• supporting the structural formation of the skeletal system
• maintaining body fluid composition
• supporting many protein and enzyme reactions

Minerals can be found in varying amounts in a variety of foods such as meat, cereals fish, milk and dairy foods, vegetables, fruit and nuts. Trace elements are also essential nutrients that your body needs to work properly, but in much smaller amounts than vitamins and minerals and can be found in a variety of foods such as meat, fish, cereals, milk and dairy foods, vegetables and nuts.

List of vitamins important for health

Vitamin A

Vitamin A is a fat-soluble vitamin.

Recommended daily intake

• 0.7 mg daily for men
• 0.6 mg daily for women

Function

• Helps maintain the health of skin and mucus linings
• Supports normal function of the visual system, particularly night vision
• Involved in reproduction and fetal development
• Involved in repair of tissue and bone
• Involved in immune function

Source

Whole eggs, dairy, liver, greens, carrots, cantaloupes and sweet potatoes.

Vitamin B2

Vitamin B2 (riboflavin) is a water-soluble vitamin.

Recommended daily intake

• 1.3 mg daily for men
• 1.1 mg daily for women

Function

• Involved in carbohydrate, protein and fat metabolism
• Involved in iron transport and metabolism
• Helps maintain the health of skin and mucus linings

Source

Dairy, enriched grain and cereal products, dark green leafy vegetables, liver, beef, lamb, eggs, and nutritional yeast such as marmite.

Vitamin B3

Vitamin B3 (niacin) is a water-soluble vitamin.

Recommended daily intake

• 17 mg daily for men
• 13 mg daily for women

Function

• Involved in obtaining energy from carbohydrates fat, and protein
• Involved in iron transport and metabolism
• Helps maintain the health of skin and mucus linings

Source

Dairy products, whole and enriched grain and cereal products, dark green leafy vegetables, liver, beef, lamb, eggs, and nutritional yeast.

Vitamin B5

Vitamin B5 (pantothenic acid) is a water-soluble vitamin

Recommended daily intake

• 10 mg daily for adults
  

Function

• Helps convert food into energy as part of Coenzyme A (CoA)
• Involved in vitamin utilisation
• Involved in nervous system function

Source

Found in most animal and plant foods, such as beef, poultry, whole grains, legumes, tomatoes, broccoli, potatoes.

Vitamin B6

Vitamin B6 is a water-soluble vitamin

Recommended daily intake

• 1.4 mg daily for men
• 1.2 mg daily for women

Function

• Involved in carbohydrate, fat and protein metabolism
• Involved in nervous system function
• Assists in the formation of the vitamin niacin from tryptophan
• Involved in nervous system function
• Involved in immune function
• Involved in iron transport and metabolism
• Regulates blood sugar levels
• Regulates homocysteine levels

Source

Meats, fish, poultry, beans, eggs, potatoes, some fruits and vegetables such as watermelon and bananas.

Vitamin B12

Vitamin B12 is a water-soluble vitamin

Recommended daily intake

• 1.5 mg daily for adults

Function

• Involved in carbohydrate, fat, and protein metabolism
• Involved in nervous system function
• Activates the metabolically active form of folate
• Involved in red blood cell formation
• Involved in bone metabolism

Source

Meat, fish dairy and fortified foods, such as breakfast cereals.

Biotin

Biotin is a water-soluble vitamin

Recommended daily intake

• 200 mg daily for adults

Function

• Involved in carbohydrate, protein and fat metabolism
• Involved in nervous system function
• Essential in gluconeogenesis (the breakdown of protein as an energy source during starvation)

Source

Egg yolk, meat, fish, soybeans, dairy, whole grains, and dark green vegetables.

Vitamin C

Vitamin C is a water-soluble vitamin

Recommended daily intake

• 40 mg daily for adults

Function

• Powerful antioxidant
• Assists in the formation of collagen
• Involved in immune function
• Promotes iron absorption

Source

Fruit and vegetables including red bell peppers, kiwi, oranges, broccoli, strawberries, tomato juice, watermelon, potatoes, bananas, and carrots.

Vitamin D

Vitamin D is a fat-soluble vitamin

Recommended daily intake

• 5 -10 μg daily for adults
• 15 μg daily for adults of 70 years and over

Function

• Involved in immune function
• Involved in cell growth
• Involved in fetal development
• Involved in calcium absorption thus assisting in bone and teeth formation

Source

Synthesised in the skin upon exposure to the UV rays in sunlight, and also fatty fish, egg yolks and liver.

Vitamin E

Vitamin E is a fat-soluble vitamin. Any surplus intake is stored for future use.

Recommended daily intake

• 15 mg daily for adults

Function

• Powerful antioxidant protecting against the harmful effects of free radicals
• Involved in immune function
• Involved in DNA repair

Source

Green leafy vegetables, nuts, beans, whole grains, vegetables oils and fortified cereals.

Vitamin K

Vitamin K is a fat-soluble vitamin. Any surplus intake is stored for future use.

Recommended daily intake

• 120 mg daily for men
• 90 mg daily for women

Function

• Involved in blood clotting
• Involved in bone protein synthesis

Source

Green leafy vegetables, cabbage, liver, milk, eggs, meats, cereals, and other fruits and vegetables.

Folic acid

Folic acid is a water-soluble vitamin and must be consumed daily.

Recommended daily intake

• 120 μg daily for men

Function

• Involved in carbohydrate and protein and fat metabolism
• Reduces risk of brain and spinal cord damage during first weeks of pregnancy
• Involved in cell division
• Involved in formation red blood cell
• Involved in converting vitamin B12 to its metabolically active form

Source

Leafy green vegetables, citrus fruits and fruit juices, dried beans and peas, poultry, enriched grain products.

Thiamine

Thiamine is a water-soluble vitamin and must be consumed daily.

Recommended daily intake

• 1 mg daily for men
• 0.8 mg daily for women

Function

• Involved in carbohydrate metabolism
• Assists in nervous system, heart, and muscle function
• Regulates appetite

Source

Pork, seafood, pinto beans, wheat germ, whole and enriched grains, potatoes, tomato juice, watermelon, and oranges.

List of minerals important for health

Calcium

Recommended Intake

• 700 mg daily for adults

Function

• Involved in bone and teeth structure
• Aids in muscle contraction, blood clotting, blood vessel contraction and dilation
• Involved in the secretion of enzymes and hormones
• Supports nerve function

Source

Dairy products, kale, chinese cabbage, broccoli, bok choy, parsley, watercress, some seaweeds and alcium fortified juice, soy milk, tofu, and cereals.

Chromium

Recommended Intake

• 0.025 mg a day for adults

Function

• Maintains normal blood sugar levels by increasing the effectiveness of insulin.

Source

Meat (especially liver), peas, beans, cheese, whole grains, brewer’s yeast and red wine.

Copper

Recommended Intake

• 1.2 mg daily for adults

Function

• Structural component of many enzyme systems
• Required for the health of bones, lungs, and blood vessels
• Involved in wound healing and collagen synthesis

Source

Legumes, fish, liver, shellfish, whole grains, cocoa powder, cereal and cereal products, green vegetables.

Iodine

Recommended Intake

• 0.14 mg a day for adults

Function

• Involved in thyroid hormone production

Source

Sea fish, shellfish cereals and grains

Iron

Recommended Intake

• 8.7 mg daily for men
• 14.8 mg daily for women

Function

• Required for formation of haemoglobin in the blood and myoglobin in the muscle
• Involved in energy metabolism
• Involved in immune function
• Helps regulate cell growth and differentiation

Source

Red meat, organ meats, fish, poultry, eggs, beans, lentils, whole and enriched grains, green leafy vegetables and dried fruits.

Magnesium

Recommended Intake

• 300 mg daily for men
• 270 mg daily for women

Function

• Involved in nerve and muscle function
• Involved in energy metabolism
• Regulates muscle contraction and blood clotting
• Essential for healthy bones and teeth
• Aids in the synthesis of proteins, fat, and nucleic acids
• Involved in immune function

Source

Green leafy vegetables, legumes, nuts, seeds, whole grains, “hard” tap water.

Manganese

Recommended Intake

• Males ≥ 19 years: 2.3 mg daily
• Females ≥ 19 years: 1.8 mg daily

Function

• Involved in energy metabolism
• Involved in bone growth and development
• Antioxidant properties

Source

Vegetables, fruit, grains, bran, nuts, tea.

Phosphorus

Recommended Intake

• 550 mg daily for adults

Functions

• Required for bone and tooth structure
• Part of DNA and RNA, thus assisting in growth
• Structural component of cell membranes
• Essential for energy metabolism
• Activates enzymes and some B vitamins

Source

Present in all animal and plant foods.

Potassium

Recommended Intake

• 3.5 g daily for adults

Functions

• Maintains water and electrolyte balance
• Helps control activity of the heart, muscles, and nervous system

Source

Present in all animal and plant foods.

Selenium

Recommended Intake

• 55 μg daily for adults

Function

• Antioxidant properties
• Involved in the regulation thyroid function
• Involved in immune function

Source

Meat, chicken, seafood, fish, eggs, brazil nuts, grains, garlic, mushrooms. Present in plant foods, but varies by region and type of soil.

Zinc

Recommended Intake

• 5.5 to 9.5 mg daily for men
• 4 to 7 mg daily for women

Function

• Assists in the activity of numerous enzymes
• Involved wound healing and skin health
• Antioxidant properties
• Involved in immune function
• Involved in DNA synthesis
• Involved in reproductive development
• Regulates insulin production, storage, and release
• Helps produce the active form of vitamin A
• Assists in thyroid function

Source

Meat, poultry, seafood, eggs, milk products, whole grains, fortified cereal, legumes.