Selenium is a trace element that is found in all the cells of the body. An adult contains around 10-15 mg of selenium with the largest concentrations being found in the liver, kidneys, thyroid gland, sexual gland (gonads), and semen. Selenium supports over 30 different selenoproteins that have a number of different functions. Among these are five glutathione peroxidases (GSH-Px) that function as antioxidants, and three deiodinases that regulate the metabolism. Of all minerals, selenium is the one that holds the greatest antioxidant potential. It works in close collaboration with vitamin E to prevent oxidative damage to cell membranes, lipids, and DNA. Selenium and sulfur bear great chemical resemblances, but sulfur is not an antioxidant and has other functions in the body.

Iodone is an essential trace element. An adult contains around 20-50 micrograms of iodine with 2/3 of the total supply being stored in the thyroid gland. The only known function of iodine is that it supports the two thyroid hormones that control all metabolic processes in the body. The thyroid hormones are named T3 (triiodothyronine) and T4 (thyroxine), depending on how many iodine atoms they contain. T3 functions substantially faster than T4, which is considered a precursor. Selenium is also an essential constituent of enzymes that regulate thyroid hormonal activity. Among other things, it works by removing an iodine atom, whereby the passive T4 hormone is converted to the active T3 hormone. If too little T3 hormone is produced, the metabolic rate slows down. If too much T3 is produced, the metabolic rate speeds up. For that reason, it is vital that there is enough iodine and selenium to ensure the right balance.

An adult contains around 150 grams of potassium with 98% inside the cells. Potassium works in synergy with sodium, which is primarily found outside the cells in the tissue fluids. The potassium-sodium distribution is essential for the so-called electrolyte balance of cells, and this is crucial for the cellular uptake of nutrients, for the ability of cells to get rid of waste products, and for the maintenance of essential fluid balances. The kidneys regulate the body's potassium levels and they must always be in balance with sodium. A major sodium source is table salt (sodium chloride). Excessive consumption of sodium may result in a potassium deficiency.

Copper is an essential trace element. An adult contains around 100-150 micrograms of copper. Most of it is found in the liver, brain, kidneys, and heart. Fetuses and newborn babies have particularly high copper levels in their liver. In fact, the liver is believed to serve as an extra storage facility during lactation where the copper content in breastmilk is rather low.

Cobalt is a trace element. An adult contains around one mg of cobalt, which is mainly stored in the kidneys, muscles, and bones. The nutrient is also part of the vitamin B12 molecule that is important for the formation of red blood cells and for the nervous system, among other things.

Functions and importance for

• The production of vitamin B12
• The production of folic acid
• The production of blood by means of folic acid and vitamin B12

Magnesium is an essential mineral. An adult contains around 20-30 grams of magnesium. Approximately half of the body's magnesium supply is stored in the bones. The rest is distributed in the muscles, liver, nerve tissue and other soft tissues. Magnesium is mainly found inside the cells where it supports over 300 different enzymatic processes.

Functions and importance for

• Strong bones. Together with calcium and phosphor, magnesium constitutes the solid matter of bone tissue
• Energy turnover and energy levels
• Nervous system and nerve impulse transmission
• Blood pressure and heart
• Muscle function and muscle contraction
• Maintenance of the electrolyte balance (fluid and sodium balance) with sodium and potassium
• Protein synthesis, including muscles, hormones, and skin
• Cell division
• Alkalizing agent that prevents acid overload

Manganese is an essential nutrient. An adult contains around 10-20 mg of manganese that is evenly distributed throughout the body. Only around five per cent of dietary manganese is absorbed, possibly by means of the same mechanisms as those involved in the uptake of iron. Manganese is mainly involved in different enzymatic systems such as pyruvate carboxylase and superoxide dismutase (SOD) that support the metabolism of macronutrients such as carbohydrate, protein, and fat and also work by neutralising free radicals.

Molybdenum is a trace element. An adult contains around 8-10 mg of molybdenum that is primarily found in the liver, kidneys, adrenal glands, spleen, bones, teeth, and skin. Molybdenum is incorporated in vitamin B12 and several enzymes that regulate the turnover of nutrients.

Functions and importance for

• Turnover of sulphurous amino acid
• Uric acid metabolism
• Vitamin B12

An adult contains around 100 grams of sodium. The lion's share of our sodium works in synergy with potassium and chloride as electrically charged particles called ions. Sodium and chloride are mainly found in the tissue fluids outside the cells, while potassium is mainly found on the inside of the cells. This distribution is vital for the cells and their so-called electrolyte balance that controls cellular uptake of nutrients, waste product excretion, nerve impulses, and the maintenance of essential fluid balances. The kidneys regulate the sodium levels, and it is vital that they are in balance with the body's potassium levels. A major sodium source is table salt (sodium chloride). If we ingest too much sodium it may cause a potassium deficiency and subsequent health problems.

Iron is one of most important trace elements because of its role in the hemoglobin of the red blood cells that deliver oxygen to all cells and tissues in the body. Around two thirds of the body's total iron supply is found in the red blood cells and in muscle tissue. Around a third of our iron is stored in the liver, spleen, and bone marrow where the red blood cells are produced. A very small amount is used in vital enzymes in the brain, among other places. The organism has a limited ability to excrete iron through the intestinal system, the bile, the urine, and the skin. Moreover, iron is excreted through menstrual blood and breastmilk. An adult contains around 3-6 grams of iron. One litre of blood contains around 500 mg of iron. It is iron that gives blood its red colour, and the oxygenated blood in our arteries is lighter than the deoxygenated blood in our veins.

Sulphur is essential for plants and animals. An adult contains around 175 grams of sulphur. The nutrient is found in the amino acids cysteine and methionine and is therefore also present in all the proteins and enzymes that contain these amino acids. Sulphur is a component of those enzymes that are responsible for ensuring that the hemoglobin in red blood cells is able to bind oxygen. Sulphur is also a component of the disulfide bonds that give strength to skin, hair, and nails. The reason why bird eggs have such a high sulphur content is that the nutrient is needed for the plumage of the developing bird. Sulphur is able to bind heavy metals and other toxins. Sulphur is chemically similar to selenium, but sulphur is not an antioxidant and has other functions in the body.

Zinc is a trace element that is found in all cells and body fluids. Zinc is essential for normal functioning of around 200 different enzymes that control growth, metabolism, the nervous system, the immune function, and a variety of other functions. Most of our zinc is found in muscle tissue and bone tissue and there is a rather large zinc concentration in the prostate gland and in the choroidal membrane of the eye. Around 11% of our zinc is found in the skin and liver. An adult contains 2-4 grams of zinc. We are only able to absorb 10-30% of the zinc that we get from our diet, and there are several factors that can either increase or decrease zinc absorption.

Q10 is a lipid-soluble coenzyme that is found in all the body's cells, except for the red blood cells. Carbohydrate, fat, and protein get converted into energy by means of Q10 and the oxygen we breathe. This process takes place inside the small, cellular power stations called mitochondria. To begin with, Q10 contributes to storing the energy in a chemical form called ATP (adenosine triphosphate). After that, Q10 makes sure that the energy is released in step with the shifting energy requirement of the cells.

Heart, brain, muscle, liver, kidney, and sperm cells contain particularly many mitochondria and large amounts of Q10, as they are highly dependent on energy. Q10 also functions as an antioxidant that protects cells and their mitochondria against DNA damage. We human produce most of the Q10 we need but this ability deteriorated with increasing age.

Omega-3 fatty acids belong to a group of polyunsaturated fatty acids. Their "omega-3" name indicates that they have a double bond at the third carbon atom in the middle carbon chain. Omega-3 fatty acids provide energy and constitute an important element in all cell membranes and various biochemical processes. The type known as ALA (alpha-linoleic acid) is essential, as the human body is unable to produce it. We depend on a dietary supply of this fatty acid. By means of enzymes, ALA is converted to EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) and finally into some hormone-like substances named prostaglandins (E3).

The conversion from ALA to EPA and DHA is often limited, perhaps because of lacking enzymes. For that reason it is believed that many people are able to benefit more from EPA and DHA when these fatty acids come directly from the diet (mainly from oily fish) or in the form of supplements (fish oil supplements). Human and animal brains contain large amounts of omega-3 and omega-6 that ensure integrity in the neurological network. DHA (and to a lesser extent EPA) is particularly important for a special type of enzyme activity called NOS (nitric oxide synthase activity) and is highly important for memory and learning.

Omega-6 fatty acids belong to a group of polyunsaturated fatty acids whose "omega-6" name indicates that they have a double bond at the sixth carbon atom in the middle carbon chain. Omega-6 fatty acids provide energy and they are constituents of cell membranes and numerous biochemical processes. The type called LA (linoleic acid) is essential, as we humans are unable to synthesise it in the body. We depend on LA from our diets. Helped by certain enzymes, LA gets converted to GLA (gamma-linolenic acid) and further on to AA (arachidonic acid) and some hormone-like substances called prostaglandins (type E1 and E2). The omega-6 fatty acids work together in a biochemical teamwork with omega-3 fatty acids. The type of fatty acids and the mutual balance between them is important for various processes.

CLA (conjugated linoleic acid) is a group of omega-6 fatty acids, of which there are 28 different varieties. A few of them are associated with health benefits. This is the case with the following two types, Trans-10,Cis-12 and Cis-9,Trans-11

The healthy CLA types are found naturally in meat (from ruminants) and dairy products (especially those with high fat content). In order to obtain optimal levels of CLA, the animals must graze, as this causes their gut bacteria to convert linoleic acid to CLA.

Dietary fibres are coarse, indigestible carbohydrates. They are constituents of cell walls in plants and differ from starch and sugar by their inability to be broken down by the digestive enzymes in the gastro-intestinal tract. For that reason, dietary fibre hardly provides any energy on its way through the digestive system. On its passage through the system, fibre affects the intestinal contents and its transit time, which benefits the digestion and also provides secondary health benefits.
Dietary fibre is divided in two groups: Soluble and insoluble fibre types.

Lactic acid bacteria are many different types of bacteria that produce lactic acid by fermenting carbohydrate. They are widespread in the kingdom of plants and animals. Lactic acid bacteria are also called probiotics which means "pro life" and constitute a vital part of our enormous intestinal microflora that contains more bacteria than body cells and weighs around two kilos.

Lactic acid bacteria also constitute an important part of the vaginal microflora. At birth, lactic acid bacteria and other vital micro organisms are transferred to the baby via the birth canal and via breast milk. The baby's microflora is considered to be fully developed around the age of three years.

The most common term for this nutrient is folic acid, whereas vitamin B9 is hardly ever used. Folic acid is the synthetic form that is found in vitamin pills, while folate and folacin are the forms of the nutrient that are found naturally in food. Folic acid is very stable and gets converted into folate in the body. The vitamin is water-soluble. Most of it gets stored in the liver, which contains around half the body's total amount of folate. The nutrient is destroyed by boiling and heating.

Functions and importance for

• Cell division in the body
• Energy levels
• Fertility (male and female)
• Tissue growth and development during pregnancy
• Synthesis of amino acids - the building blocks of protein
• Formation of red blood cells (that carry oxygen to all the tissues in the body)
• Blood levels of the amino acid homocysteine
• Mental balance
• The immune system
• Reduction of fatigue and exhaustion

Pure vitamin A (retinol) is a lipid-soluble vitamin. It is primarily found in animal sources that contain fat. Vegetable sources contain a lipid-soluble precursor of vitamin A called beta-carotene. Pure vitamin A is primarily stored in the liver and in fatty tissue, for which reason we do not need a daily supply of the nutrient. Vitamin A and zinc work together. A deficiency in one nutrient will therefore affect the other. On a global scale, vitamin A deficiencies are widespread. In Western countries vitamin A deficiency is normally seen in connection with chronic disease. Vitamin A is destroyed when exposed to oxygen or heat, for instance during cooking.

B vitamins are water-soluble and because they do not get stored in the body, we humans depend on regular intake of them. B vitamins work in synergy in a highly complicated teamwork setup. They take part in most of the body's enzymatic processes, some more actively than others. The uptake of B vitamins depends on gastric acid and digestion.

B vitamins:

Vitamin B1 (thiamine)
Vitamin B2 (riboflavin)
Vitamin B3 (niacin)
VitaminB5 (pantothenic acid)
Vitamin B6 (pyridoxine)
Biotin (vitamin B7, vitamin B8, vitamin H)
Folic acid (folate, folacin, vitamin B9)
Vitamin B12 (several types of cobalamin)

Vitamin B1 is water-soluble and because it does not get stored in the body we depend on regular intake of the nutrient. In the 1920s, the Japanese scientist Umetaro Suzuki discovered vitamin B1 in rice shells and observed that this nutrient counteracted the classic deficiency symptom beriberi. Vitamin B1 is destroyed by alkaline substances and heating but not by freezing

Functions and importance for

• Energy metabolism and carbohydrate metabolism
• Normal energy levels
• Normal nervous and brain function
• Maintenance of psychological balance
• Normal muscle and heart function
• Production of hydrochloric acid in the stomach and normal digestion
• Antioxidant that protects against free radicals

Vitamin B2 is water-soluble and because it does not get stored in the body we depend on regular intake of the nutrient. Vitamin B2 is also known as lactoflavin and is used as a yellow colouring agent/additive in various foods. When ingested in very large quantities vitamin B2 causes the urine to turn highly yellow. Vitamin B2 is destroyed by light, heating, and alcohol.

Vitamin B3 is water-soluble and because it does not get stored in the body we depend on regular intake of the nutrient. Niacin is a common term for nicotinic acid and nicotinamide. The body's metabolism is able to synthesise part of its required niacin from vitamin B6 and tryptophan, an amino acid which is primarily found in meat. Vitamin B3 is destroyed by heating.

Functions and importance for

• Energy metabolism (turnover of carbohydrate, fat, and protein)
• Energy levels
• Vasodilation
• Circulation and cholesterol balance
• Nervous system
• Mental balance
• Skin and mucous membranes
• Reduction of fatigue and exhaustion

Pantothenic acid originates from the Greek word pantos, which means everywhere. As the word suggests, this vitamins is found in both plants and animals. Vitamin B5 is water-soluble and because it does not get stored in the body we depend on regular intake of the nutrient. Vitamin B5 is destroyed by heating and freezing.

Functions and importance for

• Energy turnover
• Building block of enzymes that are used to burn carbohydrate, fat, and protein
• Nervous system. Involved in the synthesis of signaling substances (neurotransmitters)
• Mental balance
• Digestion. Involved in the production of bile acid
• Involved in the synthesis of cholesterol and vitamin D
• Involved in the synthesis and metabolism of steroid hormones such as sex hormones and corticosteroids
• Reduction of fatigue and exhaustion

Vitamin B6, also known as pyridoxine, is converted to the active forms, pyridoxal phosphate and pyridoxamine phosphate. Vitamin B6 is water-soluble and because it does not get stored in the body we depend on regular intake of the nutrient. Vitamin B6 is destroyed by heating and light.

Functions and importance for

• Energy turnover, especially the metabolism of protein and glycogen (sugar stored in the liver and muscles)
• Energy levels
• Blood levels of the amino acid homocysteine
• Nervous system
• Mental balance
• Formation of red blood cells that carry oxygen to all parts of the body
• Immune system
• Regulation of hormonal activity
• Reduction of fatigue and exhaustion
• Antioxidant that neutralises free radicals

There are various forms of biotin and they all belong to the family of B vitamins. Biotin is synthesised from bacteria (including gut bacteria) and mold and yeast fungus, algae, and certain plants. Biotin is water-soluble and because it does not get stored in the body we depend on regular intake/production of the nutrient. Biotin is removed when boiled in water.

Why do we need supplements in some situations?

We humans depend on an array of different nutrients in order to thrive and be able to prevent various diseases. However, even with a healthy and balanced diet there may be circumstances that call for the use of supplements:

• Depleted soil typically lacks minerals and trace elements
• The process of refining, boiling, frying, and exposing food to other types of thorough preparation reduces its content of many different nutrients
• In our part of the world, we are unable to synthesise vitamin D from sunlight during the winter period 
• Environmental pollution, stimulant abuse, and the use of medicine challenges the body's immune defence and cleansing organs
• Stress, pregnancy, lactation, age, disease, and high-performance sports activities often increase the need for a number of different nutrients

Vitamin B12 is a common term for a group of chemically related substances that all have vitamin activity. They are also known as cobalamins. The biosynthesis of the basic structure is handled by bacteria that are found many places in nature. The uptake of vitamin B12 from food requires the presence of the protein intrinsic factor that is formed in the gastric mucosa. Intrinsic factor binds to vitamin B12 and transports it into the body from the small intestine. Coli bacteria in the colon also produce vitamin B12 that is taken up by the body. Vitamin B12 is stored in the liver for up to several months at a time, and we humans are also able to reuse vitamin B12 that has been absorbed from the intestine. It is generally more difficult for the body to absorb vitamin B12 compared with other vitamins, and our ability to take up the nutrient decreases as we grow older. The synthetic basic form of vitamin B12 is used in nutritional supplements and also as a food additive. The dosages are typically rather large in order to ensure sufficient uptake of the nutrient.

Vitamin C is also known as ascorbic acid and L-ascorbic acid. Most animals are able to synthesise vitamin C by means of a stepwise, enzymatic conversion of glucose (dextrose). However, humans, apes, guinea pigs, and certain other animals have lost this ability during evolution. The largest concentrations of vitamin C are found in the white cells of the immune defence, the pancreas, the testicles, and the ovaries. Vitamin C is water-soluble and as it is not stored in the body, we depend on regular intake of the nutrient. Vitamin C is destroyed by light, heat, boiling, freezing, preservation, and storage (including winter storage of vegetables and fruit).

There are several kinds of vitamin D with the two most important being:

Vitamin D2, ergocalciferol, that is found naturally in the plant kingdom.

Vitamin D3, cholecalciferol, that is found naturally in the animal kingdom.

Humans synthesise vitamin D (cholecalciferol) from sunlight (UV-B rays) and a cholesterol compound in the skin, which is converted to active vitamins by means of processes in the liver and kidneys. We humans are only able to synthesise vitamin D during the summer season when the sun is high in the sky. Excess amounts of the nutrient are stored in the liver for future use. Light skin produces substantially larger amounts of vitamin D than dark skin. In contrast, dark skin protects against vitamin D overproduction. As we grow older, our vitamin D production decreases. Vitamin D is also called a provitamin or hormone, simply because we are easily able to make it ourselves, and all cells in the body have vitamin D receptors.
Vitamin D is fat-soluble and is stored in the body's fat tissue when ingested in large amounts. Vitamin D is destroyed by light and heat from cooking.

Vitamin was originally isolated from wheat germ oil in 1936. The nutrient is a lipid-soluble vitamin of vegetable origin that is primarily found in fatty foods. Vitamin E includes eight different compounds called tocopherols and tocotrienols. Alpha-tocopherol is considered the most important type of vitamin E for humans, as it is the most prevalent and active form of the nutrient. The largest concentrations are found in the adrenal glands, testicles, uterus, and fatty tissues. Vitamin E is destroyed by light and freezing. Oils should be stored in a dark and cool place.

Vitamin K is lipid-soluble and was discovered by the Danish professor and Nobel Prize laureate Henrik Dam. There are three different forms with different functions. Vitamin K1 is primarily found in green plants, whereas vitamin K2 is produced by bacteria, and vitamin K3 is synthetic.

Functions and importance for (vitamins K1 and K2)

Vitamin K1 (phylloquinone)

• Blood coagulation via prothrombin, a substance that is produced in the liver
• To stop bleeding

Vitamin K2 (menaquinone)

• Calcium metabolism
• Formation of proteins that ensure normal calcium deposition in bone tissue
• Maintenance of bones (especially in combination with calcium, magnesium, and vitamin D)

An adult contains around one kilogram of calcium, which is the most abundant mineral in the human body. Bones and teeth store around 99% of our calcium and 1 per cent is used to support metabolic functions. Levels of calcium in the blood are tightly controlled, as the slightest deviations may result in serious symptoms of the nervous system and the heart.

Vitamin D is important for the uptake of calcium in the digestive system. Parathyroid hormone (PTH) that is produced in the parathyroid gland is able to increase blood levels of calcium by releasing calcium from the bones and reducing the secretion of calcium from the kidneys. That way our bone tissue functions as a depository and a source of calcium which serves to maintain a constant concentration of calcium in the blood, in muscle tissue, and in intracellular fluids.

The mineral chromium is found in various forms. Hexavalent chromium is used for industrial purposes such as chrome plating, tanning of hides, dyes, wood protection etc. This form of chromium is toxic and may cause contact dermatitis and certain cancer forms. Trivalent chromium, on the other hand, is found in biological matter such as plants and animals and is an essential nutrient. As the body's need for chromium is rather small, this nutrient is characterised as a trace element. The body stores around 4-6 mg of chromium.

An adult person contains around 800-1,200 grams of phosphor. Together with calcium, phosphor is one of the most abundant minerals in the human body and it is vital to maintain the proper balance. About 90 per cent of the body's phosphor is found in our bones and teeth. Phosphor is also an active element of many biochemical processes and even functions as the chemical compound phosphate. Phosphor is regulated in the same way as calcium where vitamin D supports the uptake from the digestive channel, a parathyroid hormone regulates the blood content of the mineral, the kidneys control the excretion, and the bones function as a storage facility.