author of the article and development Zdravý Medvěd - VLASY : PharmDr. Alice Sychrová, Ph.D.
Vitamins and minerals are important for normal cell growth and function, and their deficiency can contribute to hair loss. Supplementing them is an easy and affordable solution, which is why it is extremely important to know which vitamins and minerals are helpful in treating hair loss.
The human scalp contains approximately 100,000 hair follicles. Of these, 90% are in the anagen (active) phase, which requires essential elements such as proteins, vitamins and minerals to produce healthy hair. Micronutrients, including vitamins and trace elements, are therefore indispensable components of our diet. Significant skin and hair changes are visible in malnourished or drastically losing weight individuals. Lack of nutrition can affect both the structure of the hair and its growth. E.g. a significant reduction in carbohydrate intake results in hair loss. Loss of about 100 hairs/day is considered natural hair loss. If a greater amount of hair falls out, it is called effluvium. If the hair is not found in the places where it should naturally occur, we speak of alopecia. A number of factors are responsible for hair fall. Increased hair loss can be genetic, it can be caused by poor lifestyle, hormonal fluctuations, serious diseases, side effects of drugs or stress. Hair loss is considered a common problem by dermatologists, but it has a profound negative psychological and emotional impact on patients. Another unpleasant problem is premature graying of hair, which can be slowed down by supplying iron, vitamin D, folic acid, vitamin B12 and selenium.
If you suffer from hair loss, graying or thinning, you may be wondering if using nutrients could help improve the condition of your hair.
Vitamin A is a group of fat-soluble retinoids. This vitamin fulfills many roles in the body: it is critically needed for vision, it is involved in immune function, and it is necessary for cell growth and differentiation. Vitamin A from the diet has been shown in studies to activate hair follicle stem cells. Vitamin A exists in the diet as preformed vitamin A and as provitamin A carotenoids (derived from plants). Most vitamin A is stored in the liver. A balanced diet usually provides sufficient amounts, up to 1300 µg/day (4300 IU [international units]) for adults. Ingestion of larger quantities may be toxic. For adults ≥ 19 years of age, the tolerable upper intake for vitamin A is 10,000 IU (3,000 µg/day). But in general, excessive consumption or excessive supplementation of vitamin A can cause hair loss.
The B vitamin complex contains eight water-soluble vitamins – thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folic acid (B9) and cobalamin (B12) ) – which help with cellular metabolism. The recommended daily intake of these vitamins can be achieved through a balanced diet, with the exception of biotin, which is the only B vitamin produced by the body. Deficiency of riboflavin, biotin, folic acid and cobalamin is associated with hair loss.
Vitamin B2 (riboflavin) is part of two important coenzymes that are used in cell development, fat metabolism and energy production. The body stores only small amounts of riboflavin in the liver, heart and kidneys. Riboflavin deficiency, although rare, can cause hair loss.
Pellagra is a disease that results from a lack of vitamin B3 (niacin) and leads to photosensitivity dermatitis, diarrhea, dementia and alopecia. Alcoholism is considered the most common cause of pellagra in developed countries.
Vitamin B7 (biotin or vitamin H) is a cofactor for five carboxylases that catalyze steps in the metabolism of fatty acids, glucose and amino acids. Biotin aids cell signaling and gene regulation. Most biotin in the diet is found in protein. Dietary proteins must be broken down into free biotin, which is then stored in the small intestine and liver. Adequate intake of biotin for adults is 30 µg/day. The average dietary intake of biotin in Western countries is adequate and biotin deficiency is rare. Acquired biotin deficiency can be caused by increased consumption of raw eggs (boiled eggs are fine). Other causes of acquired biotin deficiency include malabsorption conditions, alcoholism, pregnancy, long-term use of antibiotics that disrupt normal gut flora, and medications such as valproic acid and isotretinoin intake. Evidence suggests that 50% of pregnant women are biotin deficient. There is no upper limit for biotin intake because there is no evidence of biotin toxicity. Nevertheless, a high intake of biotin can affect the results of laboratory tests and it is necessary to inform the doctor about its use. Many hair, skin and nail supplements far exceed the recommended daily intake of biotin. While symptoms of biotin deficiency include hair loss, skin rashes and brittle nails, the effectiveness of biotin in supplements
Vitamin B9 (folic acid) is another water-soluble B vitamin. Folate is a coenzyme in nucleic acid synthesis and amino acid metabolism. About half of the total body content is in the liver. The recommended dietary allowance of folic acid is 400 µg per day for adults. The tolerable upper level of folic acid is 1000 µg. Malnourished people and alcoholics are at risk of deficiency. Folic acid deficiency can cause changes in the hair, skin and nails.
Vitamin B12 (cobalamin) is essential for DNA synthesis, neurological function and red blood cell formation. The recommended dietary allowance of vitamin B12 is 2.4 µg for adults. There is no upper limit for vitamin B12 intake because it has a low potential for toxicity. The role of folic acid and vitamin B12 in nucleic acid production suggests that they may play a role in the highly proliferative hair follicle.
Vitamin C, or ascorbic acid, is a water-soluble vitamin derived from glucose metabolism. It is a powerful antioxidant that prevents oxidation of low-density lipoproteins and free radical damage. It also acts as a reducing mediator necessary for the synthesis of collagen fibers through the hydroxylation of lysine and proline. Vitamin C plays a vital role in the intestinal absorption of iron, so vitamin C intake is important for patients with hair loss associated with iron deficiency. Humans are naturally deficient in the enzyme necessary to synthesize vitamin C, so they should get vitamin C through their diet. Citrus fruits, potatoes, tomatoes, green peppers and cabbage have particularly high concentrations of vitamin C.
Vitamin D is a fat-soluble vitamin synthesized in the skin, in epidermal keratinocytes. Vitamin D obtained from the diet or synthesized in the skin is inactive and must be activated enzymatically in the body. There is evidence that vitamin D, in addition to its important role in maintaining adequate serum levels of calcium and phosphorus, also has anti-inflammatory and immunoregulatory effects. Vitamin D supports the growth and differentiation of keratinocytes. The role of vitamin D in the hair follicle is evidenced by hair loss in patients with rickets.
Tocotrienols and tocopherols belong to the group of vitamins E, which are involved in the oxidant/antioxidant balance and help protect against free radical damage. Deficiency leads to hemolytic anemia, neurological findings, and dry skin. Vitamin E deficiency is rare but can occur in fat malabsorption disorders. However, excessive supplementation can lead to hypervitaminosis E, which can increase the risk of bleeding and reduce thyroid hormone production. In addition, there is some evidence of an adverse effect on hair growth.
The most common nutritional deficiency in the world is iron deficiency, which contributes to hair loss. The mechanism of action by which iron affects hair growth is not exactly known. Presumably, iron is a cofactor of the enzyme for DNA synthesis. In addition, several genes that may be regulated by iron have been identified in the human hair follicle. The level of serum ferritin (an iron-binding protein) is considered a good indicator of total body iron stores and is relied upon as an indicator in hair loss studies. Serum calcium, serum ferritin, and vitamin D3 levels appear to play a role in premature graying of hair.
Vegans and vegetarians are at higher risk of iron deficiency because their dietary iron requirements are 1.8 times higher than meat eaters. Non-heme iron found in plants is less bioavailable than heme iron found in meat and fish. In women who experience excessive hair loss, iron deficiency is caused by menstruation. To increase the absorbability of iron, the use of L-lysine (1.5-2 g/day) is recommended. Iron supplementation can be toxic even at long-term low doses. Therefore, monitoring of serum iron levels is recommended.
Selenium is an essential trace element that plays a role in protecting against oxidative damage as well as in the morphogenesis of hair follicles. Selenium is an essential trace element required for the synthesis of more than 35 proteins. Glutathione peroxidase (an antioxidant enzyme) depends on selenium as a cofactor. Selenium deficiency occurs in low birth weight infants and patients requiring total parenteral nutrition. It can also occur in people living in a location where the soil lacks selenium. Loss of hair pigmentation has been reported in patients receiving parenteral nutrition without selenium supplementation. Hair began to repigment after 6–12 months of intravenous selenium therapy. Similar findings, including alopecia with pseudoalbinism, were found in infants receiving nutritional support. A clinical trial in ovarian cancer patients undergoing chemotherapy demonstrated a demonstrable reduction in hair loss and gastrointestinal symptoms in patients receiving selenium supplementation compared to controls. The authors concluded that the use of selenium can be a supportive element in chemotherapy. The recommended dietary allowance of selenium is 55 μg per day for individuals aged ≥ 14 years. The availability of selenium in various foods such as meat, vegetables and nuts is sufficient to cover the daily requirement. Selenium intake in excess of 400 μg per day can be toxic. Symptoms of acute or chronic selenium toxicity include nausea, vomiting, brittle and discolored nails, hair loss, fatigue, irritability, and bad breath.
Zinc is an essential trace element, meaning that the body cannot make it on its own; it must be supplied through the diet. The main sources of zinc are fish and meat. Zinc is required by hundreds of enzymes and numerous transcription factors that regulate gene expression. Its exact mechanism of action on hair growth is unclear, but one possibility centers on zinc's role as an essential component of many metalloenzymes important in protein synthesis and cell division. Zinc deficiency may occur in patients consuming large amounts of cereal grains (which contain phytate considered a zinc chelating agent), in those with insufficient meat consumption or parenteral nutrition, and in infants on milk formula. Other causes of zinc deficiency include anorexia nervosa, inflammatory bowel disease, and cystic fibrosis. Alcoholism, cancer, burns, infections and pregnancy can all cause increased metabolism and excretion of zinc. Hair loss is a well-known symptom of zinc deficiency, which can be reversed with zinc supplementation. But beware, excessive supplementation of zinc can have a toxic effect. Acute side effects include pain, vomiting, and diarrhea, while chronic effects include interaction with iron and reduced immune function.
A lack of polyunsaturated essential fatty acids such as linoleic acid (omega-6 fatty acid) and alpha-linolenic acid (omega-3 fatty acid) can be the result of inadequate nutrition. Hair reacts to their lack by falling out and becoming lighter, thinning of the eyebrows also appears. Unsaturated fatty acids work by modulating the action of androgens by inhibiting the enzyme 5α-reductase. Arachidonic acid, an omega-6 fatty acid, promotes hair growth by increasing new follicle formation.
Amino acids and Proteins
Protein malnutrition can lead to hair changes that include thinning and hair loss. One study found that taking L-lysine (an essential amino acid) improved iron and zinc absorption. One study involved L-cysteine, a component of keratin, in combination with medicinal yeast and pantothenic acid. Other studies have evaluated supplements containing marine proteins in conjunction with many other nutrients. The results of these studies suggest the safety and efficacy of these combinations in promoting hair growth and reducing hair loss in women with temporary hair thinning.
Antioxidants are compounds that are able to neutralize reactive oxygen species (ROS), thereby preventing oxidative damage. Many substances can be classified as antioxidants, including zinc, selenium, and vitamins A, C, and E, as well as polyphenols. Oxidative stress is associated with hair loss. In a clinical study, it was shown that the hair of patients with androgenic alopecia has an excessive production of free radicals. While dietary antioxidants play a key role in boosting our endogenous antioxidant system, high doses of exogenous antioxidants (perhaps from dietary supplements) can actually disrupt the balance between oxidation and antioxidation. E.g. polyphenols have antioxidant properties at low concentrations but can promote ROS formation at higher concentrations. Compounds in plant foods such as fruits, vegetables and grains may be safer and healthier compared to isolated high doses of antioxidants present in dietary supplements.
Risk factors that can cause nutritional deficiencies to contribute to hair loss
Iron deficiency can be caused by blood loss, typically during menstruation, or is associated with diseases of the gastrointestinal tract and drugs that reduce stomach acid. A disorder of food intake and absorption is characterized by a deficiency of many vitamins. During pregnancy, women require an increased intake of iron, folic acid and zinc. Alcoholics show deficiency of folic acid, zinc and niacin. Cancer patients usually lack iron and zinc. Insufficient kidney function leads to depletion (lack) of selenium and zinc. Certain medications cause nutrient deficiency, such as antiepileptic drugs that cause biotin and zinc deficiency, antihypertensive drugs that affect zinc levels, long-term antibiotic use that causes biotin depletion, and isoniazid therapy that causes niacin deficiency. Insufficient exposure to sunlight can cause low levels of vitamin D. Eating too much egg whites can affect the amount of biotin absorbed.
Many people consider healthy looking hair to be a symbol of health and beauty. And like any other part of your body, hair needs different nutrients to grow and look its best. Supplementation with vitamins and micronutrients is therefore essential for healthy hair and prevention of hair loss. No less important is the discussion about the potential toxicity of some of these nutrients. Excessive supplementation of some nutrients can result in a toxic effect. It is worth noting the negative effect of excessive supplementation of vitamin A, vitamin E and selenium, which can actually lead to hair loss.