It is important to note that the most well known dietary factors to affect hair are deficiencies of Protein and Iron. It is also thought that hair can be affected by iron deficiencies with no clinical signs of anaemia, when haemoglobin levels have tested as ‘normal’. (See mineral deficiencies and hair loss)
Food is a vital part of existence, growth and repair of the body. The production and health of the hair is dependent on the nutrients that it receives from the blood supply. Nutrients metabolised from food are carried in the blood supply to the lower part of the hair known as the hair bulb. Hairs are made from a protein like substance called Keratin. This process of manufacture is called Keratinisation and a hair bulb on the scalp produces around 0.35mm of hair per day. The metabolic requirements of cells that make up the keratin must be available at the time of the new hair growth cycle or optimal hair growth may be compromised. Meaning that certain vitamins and minerals must be present in adequate proportions at the start of a new anagen cycle or there is a likely chance of impaired or scant growth. (See Hair structre)
During active growth, cells of the hair require adequate amounts of certain nutrients: Proteins, minerals, vitamins, water, Carbohydrate and fats are all essential. Nutritional problems may develop due to the body ineffectively breaking down and distributing the nutrients required. Are you getting enough? Below is a detailed description of each of the required nutrients, including its role in the body and dietary sources.
Protein is an important substance in building tissues, often in combination with certain minerals and is needed for growth and repair of the body. The building blocks of protein are known as amino acids. Amino acids are compounds containing carbon, hydrogen, oxygen, nitrogen and, in some cases, sulphur. All amino acids have an acid group and an amino group attached to a carbon atom. Cystine and tyrosine are the most important amino acids to the hair. The amino group of one amino acid can link with the acid group of another amino acid to form a chain of amino acids. This type of link is called a peptide bond. When two amino acids are joined together a dipeptide is formed; when many amino acids join, a polypeptide is formed. There are about twenty different amino acids commonly found in plant and animal proteins. Protein from food is broken down by digestion into amino acids, which are then absorbed and used to make other proteins in the body; these are known as essential amino acids. The body is also able to make some amino acids for itself. These are known as non-essential amino acids.
The essential amino acids for adults are:
The 10 non-essential amino acids that the body can produce are:
Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well.
Cystine is the main amino acid found in hair and by directly increasing the Cysetine content in the diet, by supplements, an improvement to the hair and skin can be brought about. Cysetine is converted to Cystine through digestion. The body more readily absorbs cysetine than cystine so most supplements contain cysetine rather than cystine. Cystine is particularly abundant in skeletal and connective tissues and in hair, and is present in digestive enzymes digestive enzymes. (See Hair supplements )
Minerals are inorganic substances required by the body for a variety of functions including: Nerve function, constituents of body tissues and fluids; teeth and bone formation and components of enzymes. Some minerals are needed in larger amounts such as calcium, phosphorus, magnesium, sodium, potassium and chloride. Others are required in smaller quantities and are often referred to as ‘trace minerals’. These are iron, zinc, iodine, fluoride, selenium, copper and manganese. Both types of minerals are equally important to the body.
Calcium is a mineral generally associated with the formation of teeth and bones. The majority of the calcium in the body is to be found in the bones and teeth, with a small amount found in the tissues such as muscle. As well as teeth and bone formation, the function of calcium includes blood clotting, as it stimulates the release of chemicals required from blood cells to aid clotting. In addition, the absorption of vitamin B12 is dependant upon calcium. A dietary deficiency of calcium will cause the body to obtain calcium from the bones to compensate. Calcium deficiency can be a factor in diffuse hair loss (See mineral deficiencies and hair loss)
80% of the phosphorus in the body is present as the skeletal tissues and like calcium is also located in tissues. It is essential for the structure, function and metabolism of body cells. No other mineral has as many widely varying functions as phosphorus. A healthy intake of protein and calcium ensures adequate amounts. It is found in many foods and is unlikely to be in short supply in UK diets.
Magnesium is present in smaller amounts than calcium or phosphorus and is present in all tissues including bone. Magnesium plays a vital function in many biological reactions such as energy metabolism and electrolyte balance. In addition, it is also required for muscle function and in the transmission of nerve pulses. It is an essential element in the formation of the hair pigment and hair growth. It is present in many foods especially green vegetables but not readily available for absorption. Grains and nuts are also rich in magnesium. Deficiency is rare. However, low intakes have been observed in some groups of people.
Sodium has an essential role in the diet. It is present in the cellular fluids, fluid within blood vessels, arteries, capillaries and veins. Around half of the body’s sodium is found in these cells of the body. Its main function is to help regulate body water content and electrolyte balance and it is involved in energy utilisation and nerve function. It is also required for the absorption of certain nutrients and water from the gut. Too much salt in the diet is associated with an increased risk of raised blood pressure which is a risk factor for heart disease and stroke. A low salt diet may be used in the treatment of hypertension. Excess sweating, e.g. due to exercise in a hot environment, may cause some sodium depletion; sodium intakes may need to increase modestly and temporarily to replenish the loss in sweat.
Potassium has chemical properties similar to that of sodium but it functions differently and is found inside cells. It is also essential for water and electrolyte balance and for the proper functioning of cells, including nerves.
Chloride is widely distributed throughout the body. Chloride is a chemical your body needs for metabolism and is a part of hydrochloric acid. It also helps keep the body's acid-base balance. The kidneys carefully control the amount of chloride in the blood. Chloride in the diet is provided, primarily, by Sodium chloride (salt).
Iron is a mineral that is very important for the health of hair. It is known that anaemia, associated with low iron levels in the body, is a common cause of diffuse hair loss. Hair sometimes improves when iron intakes are raised even when there are no clinical signs of anaemia. Iron deficiency, with or without associated anaemia, has been reported in approximately 70% of women with diffuse hair fall. (diffuse hair loss)
Zinc deficiency has not been associated with hair loss quite so much but with various hair shaft defects. Zinc deficiency is likely to be from malabsorbtion as opposed to being from dietary deficiencies. It has been reported that adding Zinc to the diet can improve thyroid activity. (See thyroid disease and hair loss). Zinc plays a crucial role in promoting cell reproduction in the growth and repair of tissues. Brittle nails with white spots may indicate a deficiency in zinc. (Sources of zinc)
Iodine is required by the body for normal neurological development and for energy metabolism. However, its primary function is being an essential nutrient in the manufacture of thyroid hormones supplied by the thyroid gland. These thyroid hormones have a role in the control of a number of metabolic processes. Insufficient amounts of iodine in the diet can result in lethargy and swelling of the thyroid gland in the neck to form a ‘goitre’. (See Thyroid Disease)
Both food and water provide iodine. The level of iodine in plant foods, such as vegetables and cereal grains, depends upon the iodine level of the environment in which they have been grown, i.e. the amount in the soil or water. The only rich sources of iodine are seafoods because saltwater fish have the ability to concentrate iodine within their tissues. In some countries certain foods, such as salt and bread, are fortified with Iodine. In the UK dairy products are an important source of iodine and, as a result, iodine deficiency is quite rare in the UK.
The addition of fluoride to toothpaste is now very common and is important in those areas where the water supply is low in fluoride. It contributes to the maintenance of bone health by supporting bone mineralisation and, as such, it protects teeth against dental decay. Very large amounts of fluoride can cause mottling and crumbling of teeth and changes to the bones - a condition called ‘fluorosis’. In the UK some water supplies, where the fluoride content is low, have fluoride added in small amounts (about 1 part per million). Although fluoride is found in varying quantities in water, it is found in few foods.
The body only uses minimal amounts of this mineral. Selenium is a component found within some of the enzymes which protect the body against damage due to oxidation (free radical mediated damage) and it helps to prevent damage to cell membranes. It is also necessary in thyroid hormone metabolism and for immune system function. Sources of selenium include brazil nuts, cereals, meat, fish and eggs. Too much selenium causes selenosis, a condition that, in its mildest form, can lead to loss of hair along with poor skin and nails.
Copper Of all the copper consumed in the diet only a small amount is absorbed. Copper can be found in body tissues such as the liver and brain. One of the many functions of copper in the liver is to release iron. In hair and skin formation copper is an essential part in the formation of the disulfide bonds. It also plays a role in the formation of the pigment melanin. Dietary deficiency is extremely rare but copper deficiency may arise because of a genetic defect (Menke’s syndrome).
Manganese has the function of assisting in the making and activation of certain enzymes in the body, in particular those involved in the synthesis of cholesterol and fatty acids. High doses of manganese for long periods could lead to neurological symptoms such as fatigue and depression and even damage to the nervous system. Dietary sources are green vegetables, especially green beans and peas, bread, cereals and nuts. It is also found in tea.
Vitamins are organic compounds which are essential for the body to function properly and also essential for growth, maintenance and metabolism. They cannot be manufactured in the body and, therefore, need to be consumed through the diet. There are two types of vitamins: fat-soluble and water-soluble. Most foods contain a number of vitamins but no one food can fulfil all human requirements. Although some vitamins can be stored they cannot be stored in significant quantities, therefore a constant dietary supply must be maintained in order to avoid depletion.
This means that although the body needs these vitamins daily it does not need to consume them every day. This is because any of the vitamins that your body does not need immediately will be stored for future use. These vitamins are stored in the liver and fatty tissues of the body. It is also worth noting that, if you have much more than you need, fat-soluble vitamins can be harmful. Fat-soluble vitamins are mainly found in foods such as dairy, animal fats (including butter and lard), oils, liver and oily fish.
RDA refers to the Recommended Daily Amounts. Some vitamins are measured in IU (international units); others are measured in mg (milligrams) or mcg (micrograms). One milligram is equal to 1000 micrograms.
Vitamin A is important to the normal structure and function of the skin and mucous membranes such as areas of the digestive system, lungs, mouth and eyes. It is required for cell differentiation and for normal growth and development. It is also important for normal vision and functioning of the thyroid and adrenal glands. In addition, it boosts immune system function and promotes bone and teeth development. It is also interesting to note that Vitamin E helps with absorption of vitamin A.
You should be able to obtain all the vitamin A you need from your normal daily diet. This is 0.7 mg per day for men and 0.6 mg per day for women.
Vitamin D has a number of important functions. It’s essential role, however, is to help utilise phosphorous in the bones. It assists in regulating the amount of calcium and phosphate in the body by promoting their absorption from food within the intestines. Both of these minerals are essential for healthy teeth and bones. After absorption, along with fats, in the intestine it can then be stored, primarily in the liver. Vitmain D can also be derived from sunlight. This is because activation of UV radiation, caused by the skins exposure to the sun, pomotes vitamin D synthesis in the body. The level of exposure and the amount of skin pigmentation can affect the levels of absorption. The more pigment in the skin the less Vitamin D is produced in the body. Adequate amounts of vitamin D can be made in the skin only after ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands or back without sunscreen. With longer exposure to UVB rays an balance occurs in the skin and the vitamin simply degrades as fast as it is generated. Deficiency results in impaired bone mineralization which may lead to bone softening diseases such as rickets. Also, deficiency could possibly contribute to osteoporosis.
The recommended daily amount of Vitamin D is 400 IU for adults and 500 - 1000 for children. Pregnant women should have between 400 - 800 IU per day.
Vitamin E has many important functions. For example, it helps protect cell membranes by acting as an antioxidant; this means it reduces oxidation, maintaining a consistency of the cell membranes. Another of its functions is to assist with the synthesis of coenzyme Q10 which is a vital element in the release of energy from carbohydrates and fats.
This vitamin also has a chemical link to sex hormones and a deficiency can lead to degeneration of sperm quality. It also has an association to Pituitary gland function; it can therefore have an effect on hair growth and pigmentation. (See diet and hair loss)
The recommended daily amount of Vitamin E is 4 mg per day for men and 3 mg per day for women.
Vitamin K, like some of the other fat-soluble vitamins, is absorbed in the small intestine. The presence of bile is essential for its absorption. Bacteria in the intestinal tract can synthesise vitamin K but only a small amount of this vitamin is required from what is consumed during the normal diet. This vitamin has a number of important functions. One of which is that it helps wounds to heal properly because it is required for the clotting of blood. There is increasing evidence that vitamin K is also required to help build strong bones.
Adults require approximately 0.001 mg per kg of body weight per day. For example, for a weight of 65 kg the requirement would be 0.065 mg per day of vitamin K. For a weight of 75 kg the requirement would be 0.075 mg per day.
Water-soluble vitamins dissolve in water and are not stored by the body in adequate amounts. They are, in fact, eliminated from the body in the urine and, as such, we require a constant supply of them in our diets. The water-soluble vitamins are known as the B-complex group and vitamin C.
Water-soluble vitamins can also be easily destroyed or depleted during food preparation or storage. Proper storage and preparation of food can minimize vitamin loss. In order to minimise this vitamin loss always refrigerate fresh produce and keep milk and grains away from sources of strong light.
This Vitamin is highly soluble in water and is the most easily destroyed of all vitamins. It can be absorbed soon after reaching the gastrointestinal tract. Vitamin C is associated with many functions including cell respiration, enzyme production and the formation of collagen. A condition known as scurvy can result from severe deficiency of vitamin C. Scurvy occurs when a failure of Collagen formation in connective tissue occurs. This failure can then break down tissue such as cartilage. This disease is characterised by bleeding gums, poor wound healing and damage to bone and other tissues. Vitamin C is also indicated as necessary for healing, particularly of scar tissue and blood levels are known to drop when tissue repair occurs. This vitamin has also been associated with its ability to improve infectious diseases as it has an effect on harmful bacteria. Probably its most known association is with the mineral Iron. This is because it facilitates the absorption of Iron in the intestinal tract keeping it in a readily soluble form, thus improving uptake of Iron. Certain effects on the body can cause vitamin C to be expended more quickly. Such effects on the body include stress, smoking, consumption of alcohol, the use of certain drugs, the healing of tissue following wounding and the experiencing of a fever and/or infection. Individuals experiencing any of the above should consume foods and drinks containing vitamin C.
Adults require 40 mg of vitamin C per day.
Due to its solubility in water Thiamine can be destroyed easily in processes such as cooking. Dietary deficiency rapidly depletes the small reserves found in tissues such as liver and muscles. Excessive amounts will be eliminated through the urine. Its main role in the body is its involvement of carbohydrate metabolism. Ultimately, it assists in the breakdown of carbohydrates into carbon dioxide and releasing energy. The amount required is relative to the amount of carbohydrate eaten. Another function of thiamine is its role in maintenance of muscle in such areas as the heart, nervous and digestive systems. Thiamine deficiency can reduce heart rate capacity and can cause poor appetite. It can even cause beri-beri, a disorder of the nervous system.
The recommended daily amount for Vitamin B1 is 1 mg per day for men and 0.8 mg per day for women.
Slightly soluble in water and easily destroyed by ultra violet light. Riboflavin can be stored in very small amounts in the liver and kidneys but mostly it is eliminated through the urine. Like Thiamine, it has a role in cell respiration but its primary functions are in the releasing of energy from glucose and the metabolism of protein, carbohydrates and fatty acids. It is also involved in the transport and metabolism of iron in the body and is needed for the normal structure and function of mucous membranes and skin. It also helps produce steroids. Ribolflavin is widely distributed in food.
The recommended daily amount for Vitamin B2 is 1.3 mg per day for men and 1.1 mg per day for women.
There are two forms of niacin: nicotinic acid and nicotinamide. Both of these forms are found in food. Niacin is required daily as it is stored in very small amounts. Niacin is required by all living cells, as its role is vital in the release of energy from all three energy building nutrients, being carbohydrates, fats and proteins. It is also important in the formation of enzymes, which aid the synthesis of these nutrients. Tryptophan is an amino acid that is a precursor of niacin. This means that Niacin can be manufactured by the body from the amino acid tryptophan. Severe deficiency of this B vitamin results in a disease called pellagra. Niacin (nicotinic acid) is found in most foods, although meat is the major source.
Adequate niacin is obtainable from a normal healthy daily diet. The recommended daily amount is approximately 17 mg per day for men and 13 mg per day for women.
Destroyed by dry heat but more stable in moist heat. The milling of wheat destroys the vitamin considerably. Pantothenic acid is present in the body as coenzyme A. All of its functions are performed through this enzyme. Coenzyme A is necessary for maintenance of normal blood sugar levels and the formation of anti bodies. Like other B complex vitamins, Pantothenic acid is involved in the metabolic processing of carbohydrates, fats and proteins. It is very abundant in foods and deficiency is uncommon.
Vitamin B6 (comprising 3 forms – pyridoxine, pyridoxal and pyridoxamine). Soluble in water, stable in heat but very sensitive to light. This Vitamin’s main involvement is in protein metabolism, being necessary as it assists the body to obtain and store energy from amino acids found in food. It is also known to affect the metabolism of fats and cholesterol. Pyridoxine is also involved in synthesising melanin and so is important to the hair. Pyridoxine plays a role in the formation of anti bodies. It is also involved in metabolism and transport of haemoglobin. Together with folate and vitamin B12, vitamin B6 is required for maintenance of normal blood homocysteine levels. Raised homocysteine is a risk factor for cardiovascular disease.
Vitamin B6 is found in a variety of foods. The recommended daily amount is approximately 1.4 mg per day for men and 1.2 mg per day for women.
A resistant vitamin, Biotin is stable in heat, light and acids. Very small amounts are stored in the tissues such as liver, kidney and brain. Biotin contributes in many biological reactions. One of its contributions is in the synthesis and oxidation of fatty acids and carbohydrates. The main role of biotin is the addition or removal of carbon dioxide. It also removes the amino of three amino acids. A large amount of Biotin can be synthesised by intestinal bacteria, therefore conditions that reduce the number of microorganisms in the intestine may reduce the amount of biotin synthesised. This is most likely why there is a link between Biotin and controlling the exacerbation of certain scalp problems. (See scalp problems).
Eating a varied and balanced diet should provide adequate Biotin. The recommended daily amount for adults is approximately between 0.01 mg and 0.2 mg per day.
The term ‘folate’ describes a group of derivatives of Pteroylglutamic acid. Folic acid is the synthetic form of the vitamin and the most stable. In its natural form it’s known as folate. It is also classed as one of the B-group vitamins as B9. Folic acid, among many things, helps tissues grow and cells work. It has a role, working along with Vitamin B12 and Vitmain C, in helping the body break down, use and create new proteins. The vitamin also helps form red blood cells and helps produce DNA, the building block of the human body which carries genetic information. It is also needed for the normal structure of the nervous system and specifically in the development of the neural tube (which develops into the spine and skull) in the developing embryo. Due to its assistance with developing of tissues cells it is also important to normal hair and skin growth. Deficiency of folate can lead to megaloblastic anaemia this is a blood disorder characterised by red blood cells that are larger than normal. Deficiency may occur from a poor diet or increased requirement, e.g. in pregnancy, from drug interaction or as a result of malabsorption. Taking the right amount of folic acid before and during pregnancy helps prevent certain birth defects including Spina bifida. Folic acid is used in supplements and for food fortification. Folate is found in small amounts in many foods. Good sources include broccoli, Brussel sprouts, asparagus, peas, chickpeas, brown rice, liver and yeast extract. Orange juice, breakfast cereals and bread may also be fortified with folic acid.
Adults need 0.2 mg per day. Before and during the early stages of pregnancy 400 micrograms (0.4mg) per day of folic acid is recommended. As it is difficult to achieve this amount of additional folate by diet alone, women’s diets typically provide about 250 micrograms (0.25mg) of folate per day, supplements are often necessary.
Vitamin B12 has a number of vital functions. It is, as with most other B vitamins, water soluble and therefore not stored by the body in any adequate amounts. This amount is around 2-5mg in adults and 80% of this is stored in the liver. It is also known as cobalamin as it contains cobalt and is entirely synthesised by bacteria. The Main function of B12 is cell division and the formation and function of blood cells. It is also needed for the normal structure and function of nerves. In addition to vitamin C, Vitamin B12 is needed to process folic acid and aids iron absorption. Dietary deficiency is sometimes seen in vegans. This is largely due to the type of omitted foods in this diet preference being those that are the main sources of vitmain B12. Therefore, in vegans who suffer from this deficiency, virtually none of this vitamin is present unless supplemented. In non-vegans when deficiency does occur, it is more typically correlated to a failure of effective absorption of B12 from the intestine, rather than a dietary deficit. To Absorb B12 effectively it is necessary for the cells lining the stomach to secret a glycoprotein, termed as the ‘intrinsic factor’. The B12-intrinsic factor complex is then absorbed in part of the small intestine with the presence of calcium. Some individuals are unable to produce the intrinsic factor. Consequently, pernicious anaemia can result and is often treated with injections of B12. The condition pernicious anaemia is when red cells are enlarged and is termed as megaloblastic. B12 is necessary for the rapid synthesis of DNA during cell division. This is particularly significant in tissues where cells are rapidly dividing, in particular the bone marrow tissues which are dependable for red blood cell formation. If B12 deficiency occurs, DNA production is disrupted and abnormal cells called megaloblasts occur. This results in anaemia. Symptoms include excessive tiredness, breathlessness and poor resistance to infection. Other symptoms can include hair loss, dry skin, a smooth sore tongue and menstrual disorders. Anaemia may also be due to folic acid deficiency, folic acid also being necessary for DNA synthesis.
Dietary supply is only found from animal sources as in meat, milk products and eggs as well as fortified foods such as breakfast cereals. Although some algae and bacteria can make vitamin B12, it is most likely not in a form that can be utilised by the body.
Adults require approximately 0.0015 mg per day.