Hair and micronutrients

It is necessary to dwell in more detail on the connection between hair loss and the content of microelements in the human body. The doctrine of microelementoses (MTOS) as diseases, syndromes and pathological conditions caused by excess, deficiency or imbalance of microelements in the human body is a huge new multidisciplinary scientific direction, better known to biologists, biochemists, physiologists, occupational pathologists, toxicologists and forensic experts than to representatives of clinical medicine. The world literature on microelements is essentially vast and has been growing exponentially in recent years. The medical aspects of the doctrine of microelements have not yet been sufficiently developed and some important sections of the pathology of human microelementoses require long-term and multifaceted research work. Pathological anatomy, histology and cytopathology of microelementoses are only being created at the present time.

The human body is 99% composed of 12 most common elements, which are among the first 20 of the periodic table of D.I. Mendeleyev; they are called structural, basic, or macroelements. In addition to them, the human body contains small (trace) quantities of heavier elements - microelements. 15 of them (iron, tin, copper, zinc, cobalt, chromium, molybdenum, nickel, vanadium, selenium, manganese, arsenic, fluorine, silicon, lithium) are recognized as essential, i.e. vitally necessary, 4 others (cadmium, lead, tin, rubidium) are considered "serious candidates for essentiality". Unlike all substances synthesized by the body, microelements enter the body from the geochemical environment. In humans, their main route of entry is the gastrointestinal tract, where the duodenum has formed a highly specialized resorption apparatus associated with blood and lymphatic vessels, as well as with the central and autonomic nervous and endocrine systems. Participating in almost all biochemical processes that regulate the vital functions of the body at all stages of its development, trace elements play a significant role in human adaptation in normal and pathological conditions. Trace element homeostasis is an important link in the general homeostatic system of the body. Each trace element has its own safe exposure range, which maintains optimal tissue functions, and its own toxic range, when the degree of its safe exposure is exceeded. It is appropriate to recall the words of Paracelsus that "there are no toxic substances, but there are toxic doses."

Endogenous genetic and congenital microelementoses (Wilson-Konovalov disease, Menkes disease, Marfan syndrome, Ehlers-Danlos syndrome) have long been known to clinicians and are caused by complex disorders of copper metabolism.

Among exogenous microelementoses, the authors distinguish natural, man-made and iatrogenic diseases. Natural diseases are associated with the peculiarities of the biogeochemical environment. Thus, endemic fluorosis, selenotoxicosis and selenium deficiency and many others, which currently have their own geography, have long been known. Endemic goiter was treated with seaweed 4,000 years ago.

Technogenic microelementoses are of particular concern. The problem of technogenic (anthropogenic) pollution is so serious that it cannot be ignored. Intoxications associated with increased levels of lead, arsenic, mercury, cadmium, nickel and other toxic microelements from the group of heavy metals have a negative impact not only on hair, but also on human health in general. It has been proven that human hair is an accumulator of microelements, and their concentration in hair can serve as an objective indicator of the content of microelements in the whole organism and in the environment. Large industrial cities are extreme habitats. It has been shown that the level of microelement pollution of the environment correlates with the severity of the imbalance of immunological indicators. The unfavorable situation affects children the most. Thus, in 1988 in the city of Chernivtsi (USSR) an outbreak of unexplained illness of children with total alopecia syndrome and neurological symptoms indicating pathology of the hypothalamus was described. A study of soil, plants and biosubstrates (blood, urine and hair) revealed an increase in the content of a number of microelements, including thallium.

Working classification of human microelementoses

Microelementoses	Main forms of diseases	Brief description
Natural Endogenous	Congenital	In case of congenital microelementoses, the disease may be based on microelementoses of the mother
	Hereditary	In hereditary microelementoses, deficiency, excess or imbalance of microelements is caused by pathology of chromosomes or genes
Natural Exogenous	Caused by micronutrient deficiency	Natural, i.e. not associated with human activity and confined to certain geographic locations, endemic diseases of people, often accompanied by certain pathological signs in animals and plants
	Caused by excess trace elements
	Caused by micronutrient imbalances
Man-made	Industrial (professional)	Diseases and syndromes associated with human industrial activity caused by an excess of certain microelements and their compounds directly in the production area itself;
	Neighborhood	next to the production;
	Transgressive	at a considerable distance from production due to air or water transfer of microelements
Iatrogenic	Caused by micronutrient deficiency	A rapidly increasing number of diseases and syndromes associated with intensive treatment of various diseases with drugs containing microelements, as well as with supportive therapy (for example, with total parenteral nutrition) and with some treatment procedures - dialysis, which do not provide the body with the necessary level of vital microelements
	Caused by excess trace elements
	Caused by micronutrient imbalances

In recent years, the importance of iatrogenic microelementoses has increased, which is associated with the treatment of various diseases with drugs containing microelements (iron, lithium, iodine, bromine, fluorine, mercury, bismuth, arsenic and many others), with parenteral nutrition, hemodialysis, therapy with D-penicillamine, L-histidine, cytostatics and other medications. It is advisable to include in the risk group all patients who have undergone resection of the proximal parts of the small intestine and stomach, as well as with pathological changes, especially atrophy, of the mucous membrane of these parts of the gastrointestinal tract (damage to the main zones of absorption of microelements).

The microelement status of the body is also affected by bad habits and physiological conditions (pregnancy, childbirth, lactation, the aging process).

It is easy to see that the causes of microelementoses coincide in many respects with the causes of diffuse (symptomatic) alopecia. It is possible that the above factors lead to a violation of microelement homeostasis and, as a consequence, to hair loss. Work in this direction seems extremely promising.

According to A.P. Avtsyn and co-authors, a significant portion of microelementoses has undoubtedly not yet been isolated, and the specific weight of each microelementoses as a factor aggravating the course of diseases of other origins has been poorly determined. Compared to the diverse and severe pathology caused by a deficiency or excess of microelements in agricultural and laboratory animals, the corresponding symptoms of human pathology appear either poor or insignificant. This hardly reflects the actual state of affairs. Works devoted to the targeted study of the condition of the skin and its appendages (hair, nails) in microelementoses are rare.

Copper

Copper is known to be necessary for pigmentation and keratinization of animal wool and human hair. With copper deficiency, hair loses elasticity; it contains more N-terminal groups of serine and glutamic acid, a significant amount of unoxidized sulfhydryl groups; the formation of disulfide bridges in keratin is disrupted. The finer mechanisms of copper participation in keratinization processes remain unclear.

Menkes disease (syn.: Menkes syndrome, kinky hair disease) is a hereditary disease caused by impaired absorption and transport of copper in the body; it manifests itself in early childhood with microcephaly, seizures, the presence of kinky hair, devoid of pigment, and focal hair loss. It is inherited in a recessive, X-linked manner.

Copper deficiency increases the predisposition to allergic dermatoses, bronchial asthma, and vitiligo.

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ]

Zinc

Zinc deficiency in animals causes changes in appetite, delayed growth and sexual maturation, infertility, parakeratosis, and baldness.

Zinc deficiency in humans is a major problem for the normal development of children, since this microelement is one of the most important factors in the homeostasis of the organs of immunogenesis, reproduction and the central nervous system.

Enteropathic acrodermatitis is a hereditary disease that occurs in children of both sexes aged 1 to 18 months as a result of zinc deficiency. It is a severe systemic disease with lesions of the skin, nails and hair, gastrointestinal tract, blepharitis and photophobia, delayed physical development, frequent superinfection with Candida fungi and coccal flora. The disease begins with lesions of the skin of the distal extremities, where foci of hyperemia with vesiculobullous elements occur. Gradually, the rash becomes more widespread and can resemble the clinical picture of candidiasis, atopic dermatitis, bullous epidermolysis, psoriasis. Hair growth disorders are manifested by baldness and changes in the hair itself. Thinning of hair in the frontal-parietal region or total baldness of the scalp is characteristic. The hair becomes thinner, breaks off, and lacks pigment. Complete absence of eyebrows and eyelashes is rare. Treatment is with enteroseptol, which indirectly improves zinc absorption in the intestine, and zinc preparations.

It is known that the zinc content in the hair of patients with extensive burns is reduced. The rate of wound healing directly correlates with the zinc level in the hair, and ulcerative lesions of the lower extremities heal faster when taking zinc sulfate.

Manganese

Hypomanganosis in children and adults can lead to delayed growth of hair and nails and contribute to the development of allergic dermatitis.

Chromium

The concentration of chromium in the hair of full-term babies is 2.5 times higher than that of their mothers. Childbirth, diabetes and atherosclerosis lead to a decrease in the concentration of this microelement in the hair. Excessive intake, especially of hexavalent chromium, can have an allergenic effect (allergic dermatitis, eczema, asthmatic bronchitis).

[ 7 ], [ 8 ], [ 9 ], [ 10 ]

Selenium

Both deficiency and excess of selenium cause damage to hair, nails and skin.

Silicon

Concentrates in the stratum corneum and hair cuticle, being part of the alkali-insoluble component, which gives these substances chemical resistance. Apparently, this microelement also accumulates in the hard keratin of the nail plates, since its deficiency causes brittle nails.

Barium

Chronic intoxication with barium and its salts, along with general symptoms, is characterized by hair loss on the head and eyebrows.

[ 11 ], [ 12 ]

Thallium

Thallium has been shown to be a selective poison for hair follicle cells; a dose of 8 mg/kg is sufficient for total hair loss within 2-3 weeks. Thallium toxicosis is accompanied by atrophic changes in the skin and subcutaneous fat, and keratinization. Histologically, spindle-shaped thickening of the hair root with massive deposition of black pigment is detected. This pigment is also deposited in the dermis near the hair follicle, which is considered a pathognomonic sign of thallium poisoning.

Information on the influence of macroelements on hair condition is even more sparse. Thus, it is indicated that calcium plays an important role in the functioning of various body systems, including skin. It is known that patients with focal alopecia have reduced magnesium concentration in hair, and in psoriasis, arthritis and a number of therapeutic and endocrine diseases, the content of this microelement is increased.