Vitamin deficiency is the complete absence of one or more vitamins in the human body. The disease develops with insufficient intake of nutrients from food, violations of the processes of splitting, absorption or transportation of substances, may be a consequence of congenital genetic diseases. Symptoms are determined by the type and severity of vitamin deficiency. For diagnosis, an analysis is carried out for the level of vitamins in the blood serum, clinical, biochemical blood test. Treatment includes correction of vitamin balance by diet or drugs, if possible — elimination of the root cause of endogenous vitamin deficiencies.
In the medical literature, two concepts are used: vitamin deficiency, which means the complete absence of a certain vitamin compound, and hypovitaminosis, in which the body receives an insufficient amount of nutrient. Hypovitaminosis is widespread in the USA everywhere: signs of moderate deficiency of at least one vitamin are observed in 70-100% of the population, but the symptoms of vitamin deficiency are much less common. Due to the high prevalence and negative impact on health, the problem of vitamin deficiency remains one of the most urgent in medicine.
The main cause of vitamin deficiency is an unbalanced diet, as a result of which a person does not receive the necessary vitamins. This situation is observed both with voluntary restriction in food, for example, with strict diets for the purpose of losing weight, and with forced — with a low income level, in people without permanent residence suffering from drug addiction. The remaining causes of vitamin deficiency are grouped into the following groups:
- Hereditary factors. The literature describes congenital forms of hypovitaminosis caused by genetic mutations. They can affect the metabolism of any fat–soluble vitamin nutrients, as well as folic acid, compounds of group B – B1, B2, B6, B12. Signs of the condition manifest in childhood, its correction is difficult.
- Digestive disorders. Malabsorption of vitamins is observed in chronic gastroenteritis, Crohn’s disease, celiac disease, and other diseases. Symptoms appear at different stages – digestion, release of nutrients, absorption of finished bioactive forms.
- Vitamin delivery disorders. With defects in transport proteins, which most often happens with liver damage, vitamin substances do not move to target organs, therefore, symptoms of vitamin deficiency occur even with normal levels of nutrients in the blood. Disorders of the interaction of transport proteins with cellular receptors are less common.
- Disorders of cellular metabolism. In the absence of certain enzymes, the course of intracellular biochemical processes changes, which leads to the inability of the compound to turn into an active form, or “turns off” the nutrient from metabolic reactions, provoking the appearance of appropriate signs.
- Anti-vitamins. This is the name of compounds that have structural similarities with vitamins, but do not perform their functions (for example, sulfonamides, isoniazid, methotrexate). This group also includes substances capable of binding or destroying useful nutrients — thiaminases that deactivate vitamin B1, egg white avidin, which disrupts the functions of biotin.
All the above-described etiological factors of thiamine deficiency are pathological. However, there are physiological reasons for vitamin deficiency — a discrepancy between the intake of nutrients into the body and an increased need for them. This is observed in women during pregnancy, breastfeeding, in children during periods of “growth spurts”, in people who train intensively in the gym or engaged in heavy physical work.
Separately, there are disvitaminoses — conditions in which hypo- or vitamin deficiency of certain nutrients is accompanied by symptoms of hypervitaminosis of another or several vitamins. The disorder occurs due to selective absorption of nutrients in the intestine, with an unbalanced diet with a predominance of one food group. Sometimes signs of dysvitaminosis develop in those who independently take vitamin monopreparations without control.
Vitamin nutrients are divided into 2 groups: fat—soluble – A (retinol), D (ergo- and cholecalciferol), E (tocopherol), K (menaquinone, phylloquinone), water—soluble – C (ascorbic acid), B1 (thiamine), B2 (riboflavin), B6 (pyridoxine), B9 (folic acid), B12 (cyanocobalamin), PP (niacin). Vitamin-like compounds are also isolated, the deficiency of which does not cause bright clinical symptoms.
Vitamins are low molecular weight compounds that are cofactors for more than 100 enzymes necessary for the correct course of metabolic processes. This function is more inherent in water-soluble substances, which are often called enzymovitamins. Fat-soluble nutrients mainly perform signaling functions, stimulate the work of the endocrine system, for which they are called hormones vitamins.
A distinctive feature of all vitamin compounds is that they cannot be synthesized in sufficient quantities in the human body (and some substances are not produced endogenously at all), therefore, regular intake of these substances from the outside is necessary for proper metabolism. If the daily intake of the nutrient does not correspond to the physiological norm, the corresponding biochemical reactions are disrupted, clinical signs of the disorder appear.
Vitamin deficiency A
Retinol deficiency are diagnosed when the nutrient concentration in the blood is less than 0.35 mmol / l, but the first signs of insufficiency occur already at 0.7-1.22 mmol / l. The pathognomonic symptom of the condition is “chicken blindness”, characterized by a sharp decrease in vision at dusk and darkness. At the same time, in the daytime, with bright artificial lighting, patients do not complain about the deterioration of the vision of objects.
With hypovitaminosis, dryness, redness, itching of the skin, increased hair loss, brittle hair, deterioration of the nail plates are bothered. Patients feel constant fatigue, lose their sense of smell, and are disgusted with food. Vitamin deficiency can provoke the appearance of anemia, decreased fertility, stone formation in the kidneys. Retinol is one of the factors of immune reactions, so the disease is accompanied by increased susceptibility to respiratory infections.
Vitamin deficiency D
Signs of hypovitaminosis occur with a decrease in the serum vitamin concentration of less than 30 ng/ ml, deficiency is determined at an indicator below 20 ng/ ml, and severe osteomalacia is formed at a nutrient level of less than 10 ng/ml. The symptoms of vitamin deficiency D are manifested by deep violations of phosphorus-calcium metabolism, which affects the condition of bone tissue, tooth enamel, hair, nails.
In adults, the pathology is manifested by pain in the bones, muscle weakness, coordination disorders, a tendency to falls. Gradually increasing osteoporosis and osteomalacia increase the risk of pathological bone fractures that do not heal well. In children with hypovitaminosis, rickets develops with a characteristic clinical picture: growth retardation, neurological symptoms, the appearance of pathognomonic signs in the form of bone thickenings (rickets beads).
Vitamin deficiency E
Total vitamin deficiency has not been described, cases of hypovitaminosis E are found everywhere. The disease is manifested by slowly increasing muscle weakness, impaired sexual function, spontaneous abortions often occur in women due to vitamin deficiency. Signs of tocopherol deficiency are hemolytic anemia, demyelination of nerve cell axons, which is associated with cerebellar ataxia, peripheral neuropathies.
Vitamin deficiency K
The condition is typical for newborns who have not received timely prevention. In adults, signs of vitamin deficiency appear only against the background of concomitant pathology, improper collection of drug therapy. Symptoms of K deficiency are manifested by spontaneous nasal, gastric, pulmonary bleeding, hemorrhages in subcutaneous tissue, joint cavities.
Vitamin Deficiency C
Severe ascorbic acid deficiency causes scurvy — a dangerous disease, the characteristic signs of which are bleeding gums with subsequent tooth loss, hemorrhages in soft tissues, natural body cavities, heart and kidney damage. In the recent past, scurvy was widespread, usually ended with the death of the patient, but thanks to the development of medicine, pathology is practically not found at present.
Signs of moderate vitamin deficiency – weakness, spot skin hemorrhages, swelling, redness of the gums. Due to the fragility of the capillaries, an exacerbation of rosacea is possible if the patient has such a problem. Symptoms of hypovitaminosis also include slow wound healing, joint pain, premature skin aging. With a possible decrease in immunity, the risk of getting a viral or bacterial infection increases.
Vitamin deficiency of B vitamins
All compounds of group B are cofactors of energy exchange reactions. With hypovitaminosis of any nutrient, a person experiences severe weakness, intolerance to physical exertion, signs of deterioration of mental performance. Typical complaints are periodic headaches, dizziness, shortness of breath, accelerated heartbeat. Specific clinical symptoms depend on the type of thiamine deficiency.
With thiamine deficiency (B1), thiamine deficiency disease develops, which has 3 clinical forms. Signs of the “dry” form include impaired sensitivity of the lower extremities, paresthesia, cramps in the calf muscles. “Wet” thiamine deficiency is manifested by myocardiodystrophy, visual impairment, peripheral circulatory disorders. In the cerebral variant (Wernicke-Korsakov syndrome), hemorrhagic polyencephalitis occurs.
The pathognomonic symptom of vitamin deficiency B2 is cracks in the corners of the mouth, which are called angular cheilitis. Glossitis is also a concern — hyperemia, swelling, burning of the tongue, skin lesions — peeling, seborrhea, and in the later stages – symptoms of peripheral neuropathies. Lack of B6 have similar signs: glossitis, cheilosis, peripheral nerve damage, in addition, normoblastic hypochromic anemia is possible.
Vitamin deficiency B12 is called Addison-Birmer disease or pernicious anemia. The main signs of the condition: megaloblastic anemia, funicular myelosis, various forms of mental disorders. With folic acid deficiency, symptoms of megaloblastic anemia also appear, the immune system is disrupted, and the body’s natural resistance to viral pathogens decreases.
Rare types of thiamine deficiency
With insufficient biotin (vitamin H), dermatitis develops, the symptoms of which include redness, peeling of the skin, increased secretion of the sebaceous glands. Occasionally biotin deficiency is manifested by hair loss, brittle nails, drowsiness, depression. The lack of flavonoids (vitamin P) is characterized by bleeding gums, spot hemorrhages on the mucous membranes, skin, painful sensations in the legs when walking.
Thiamine deficiency are severe disorders that, without timely correction, can cause death. If there are no C and K, the main problem is massive bleeding, hemorrhages. B12 deficiency is fraught with life-threatening anemia. The lack of B1 is complicated by neuropathies, diseases of the cardiovascular system. At the present stage of medical development, fatal cases rarely occur.
With hypovitaminosis, the symptoms are less pronounced, but with their untimely diagnosis, negative consequences are possible. In addition to specific signs of vitamin deficiency, patients face mental disorders — neurosis, depression, suffer from a deterioration in the quality of life, a decrease in physical and intellectual performance.
The symptoms of vitamin deficiency are usually quite specific, so they can be suspected during a clinical examination of the patient by a general practitioner (family doctor, therapist or pediatrician). Particular attention is paid to finding out the nature of the patient’s diet, whether he has signs of chronic gastrointestinal diseases or other risk factors. Advanced diagnostics includes the following methods:
- Determination of the level of vitamins. This is the main analysis used to confirm the diagnosis. If signs of a lack of fat-soluble forms are detected, it gives the most accurate results, but fluctuations in water-soluble nutrients during the day can cause a diagnostic error, therefore, with questionable data, a second study is necessary.
- Blood test. A hemogram is performed to assess the amount of hemoglobin, the number and shape of red blood cells, which is necessary to identify laboratory symptoms of different types of anemia. A coagulogram is necessarily performed to assess blood clotting. If necessary, a biochemical study of the level of electrolytes, acid-base balance is prescribed.
- Hormonal test. With possible signs of hypovitaminosis D, the determination of the content of parathyroid hormone is shown. Symptoms of fertility disorders with a lack of A and E are a reason for an extended study on sex hormones (estrogens, progestogens, androgens), gonadotropins of the pituitary gland.
- Instrumental methods. To find out the cause of vitamin deficiency, gastrointestinal studies are necessary: fibrogastroduodenoscopy, radiography with barium passage through the intestine, CT or MRI of the abdominal organs. If vitamin D deficiency is suspected, radiography of skeletal bones is recommended.
In case of exogenous vitamin deficiency caused by an unbalanced diet, isolated dietary therapy is possible to eliminate the symptoms of hypovitaminosis. A prerequisite for such treatment is a satisfactory condition of the patient, the absence of signs of pathologies of the digestive system, a person’s willingness to strictly comply with medical recommendations, strictly adhere to the nutrition plan.
In most cases, dietary therapy is supplemented with vitamin preparations used orally for mild forms of the disease. In severe deficiency, medications are administered parenterally. To correct the signs of vitamin deficiency, there are monopreparations and multivitamin complexes. Medications, doses, administration schemes are selected individually by a specialist. In addition to vitamin therapy, the following treatment approaches are possible:
- Treatment of gastrointestinal diseases. After the elimination or stabilization of chronic inflammatory diseases of the stomach, small intestine, the processes of vitamin digestion and absorption improve.
- Correction of malabsorption. To stimulate digestion, specific enzyme preparations, synbiotics that normalize the intestinal microflora, drugs based on bile acids are prescribed.
- Normalization of the electrolyte balance. The physiological level of trace elements is important for the processes of transportation, biochemical transformation of vitamins, therefore, when appropriate signs are detected, infusions of saline solutions, calcium, potassium, iron preparations are administered to patients.
Prognosis and prevention
The prognosis depends on the cause of vitamin deficiency: insufficient intake of vitamins from food is easily corrected by diet therapy or medications, and with disorders of absorption, transport or use of nutrients, it is not always possible to normalize the vitamin balance. Correction of hypovitaminosis in patients with symptoms of chronic progressive gastrointestinal pathologies remains a difficult task for gastroenterologists, therapists, nutritionists.
The main method of prevention of hypovitaminosis is the observance of a balanced fortified diet, the use of a variety of foods of plant and animal origin. It is necessary to pay attention to the seasonality of products, their freshness, the method of heat treatment, since all this affects the final level of useful nutrients. Preventive intake of multivitamin complexes is prescribed to people from high-risk groups, it is not recommended in routine practice.