[Influence of chronic immobilization stress on vitamin status in rats fed different diets].

The influence of a stress factor, widespread in modern conditions, on the vitamin status has not been studied enough. At the same time, the negative stress impact can be aggravated against the background of unhealthy nutrition, which in turn affects the vitamin status of the organism. In this regard, the goal of the research was to evaluate the effect of chronic restrict stress on the vitamin supply in rats fed a diet with adequate and increased content of fat, sugar and cholesterol. Material and methods. The experiment was carried out on 37 growing male Wistar rats (initial body weight of 45±5 g) divided into 4 groups. Animals of the 1st (control) and the 2nd groups received a complete semi-synthetic diet (CSSD) (20% protein, 10% fat, 58% carbohydrates in the form of starch, 384 kcal/100 g) for 92 days. The levels of all vitamins and mineral elements in the rats' diets were adequate for growing rats. Rats of the 3rd and the 4th groups were fed a high-calorie, high-fat high-carbohydrate diet (HFHCD) (20% protein, 28% fat, 2% cholesterol, 18% carbohydrates in the form of starch, 20% sucrose, 511 kcal/100 g). Animals of groups 2 and 4 were subjected to daily 90-minute immobilization. The concentration of vitamins A (retinol and retinol palmitate) and E (α-tocopherol) in the blood serum and liver were determined by high-performance liquid chromatography, vitamins B1 and B2 in the liver and urine, as well as riboflavin in the blood serum and 4-pyridoxic acid (4-PA) in urine were determined by fluorimetric methods. Biochemical parameters of blood serum were determined on a biochemical analyzer; the total content of fat, triglycerides (TG) and cholesterol (CH) was determined in the liver. Results. Replacing CSSD with HFHCD, both under restraint stress and without, was accompanied by an increase in liver weight by 1.8-2.0 fold, in its fat content by 2.6-3.3 fold, cholesterol by 32.6-35.3 fold and TG - by 33.0-57.6 fold (p=<0.001). An increase in alanine aminotransferase (ALT) activity by 1.7-2.0 fold (p=<0.01), in low-density lipoprotein (LDL) cholesterol level by 5.4 fold (p=<0.05) and the atherogenic coefficient by 2.5 fold (p<0.01) as well as a decrease in creatinine and urea level (p=<0.05) in blood serum were revealed. Immobilization was accompanied by a decrease in body weight, liver and liver fat in rats fed both CSSD and HFHCD (p<0.05), but didn't affect the blood serum biochemical parameters, with the exception of an increase in ALT activity. If the activity of alkaline phosphatase (ALP) did not change during immobilization of rats fed the CSSD, then in animals fed the high-calorie diet it decreased by 37.5% (p=<0.05 from the control) under its increase against the background of restrict stress by 78.7% (p=<0.01) compared to the indicator of rats of the 3rd group. Immobilization of rats treated with CSSD was accompanied by an increase in both absolute serum α-tocopherol level and concentration correlated with the level of cholesterol and triglycerides by 26.0-57.5% (p<0.05), with a simultaneous decrease in its content in the liver per 1 g of wet tissue by 22.1% (p=0.041) relative to the indicators of intact animals. Immobilization reduced the level of retinol palmitate in the liver by 2.3 times (p<0.01), but did not affect retinol level in the blood serum. At the same time, indicators of B vitamin status (the content of vitamins B1 and B2 in the liver per 1 g of wet tissue and per organ, blood serum riboflavin level, urinary excretion of riboflavin and 4-PA) did not change, with the exception of thiamine urinary excretion, which reduced compared to the control by 38.8%. In rats fed HFHCD, immobilization had no additional effect on the supply with vitamins A and E. The content of vitamins B1 and B2 in the liver in terms of the whole organ was reduced by 14.0-26.7% relative to the indicator in animals of the 3rd group, not subjected to chronic stress, only due to differences in liver weight in animals of these groups. Conclusion. The data obtained indicate that chronic stress has a negative effect on the vitamin status of the body, worsening the supply with vitamins A, E and B1, and substantiate the feasibility of studying the mechanisms of this effect in order to develop effective vitamin complexes for the treatment and prevention of diseases caused by long-term stress.

[Influence of the rat diet enrichment with oat ß-gucans on the assimilation of B group vitamins, mineral elements and lipid metabolism].

Despite the widespread use of oat ß-glucans as ingredient of foods and dietary supplements, there is insufficient data on their effect on the metabolism of vitamins and minerals. The purpose of the study was to evaluate the effect of including oat bran with a high content of ß-glucans (ß-glucan) in the diet on the absorption of micronutrients and lipid metabolism in growing rats deficient in vitamins D, group B and trace elements (iron, copper, zinc). Material and methods. After the development of micronutrient deficiency (for 23 days), in order to assess the effect of oat bran (5%) with a high content of ß-glucans on the correction of the micronutrient status of growing male Wistar rats (with initial body weight of 70.7±0.7 g), the missing micronutrients were introduced in the semi-synthetic diet deficient in vitamins D, group B, iron, copper and zinc within 7 days either along with ß-glucan (1.47%) or without its addition. Indicators of micronutrient sufficiency (riboflavin serum concentration, daily urinary excretion of thiamine, riboflavin and 4-pyridoxic acid, measured by fluorometric methods; serum concentration and urinary excretion of calcium, magnesium, iron, zinc, copper, phosphorus, measured by the atomic absorption method or using standard methods on a biochemical analyzer) and the biochemical parameters of blood serum were compared with the parameters of rats adequately provided with all micronutrients throughout the experiment. Results. Replenishment of missing micronutrients in the diet of rats with deficiency in vitamins D and group B, iron, copper and zinc for 7 days led to the elimination of deficiency of vitamins B1, B2 and B6, regardless of the presence of ß-glucans in the diet. At the same time, against the background of the presence of ß-glucans in the feed, an increase in the absorption of iron was observed, as evidenced by an increase by 1.73 times in iron blood plasma level (р<0.05) and a tendency towards its urinary excretion decrease by 1.60 fold (р<0.10) compared to animals from the control group. Adding oat bran with ß-glucans to the feed did not lead to a decrease in blood plasma level of total cholesterol and low-density lipoproteins cholesterol. The levels of high-density lipoprotein cholesterol and triglycerides in rats of all three groups did not have statistically significant differences. Conclusion. The presence of ß-glucans in the diet had virtually no effect on the absorption of B vitamins and improved the absorption of iron.

[Vitamin supply of patients with type 2 diabetes mellitus complicated by nephropathy].

Insufficient vitamin content in the diet is a risk factor for the development of various diseases and their progression, and drug therapy can also contribute to the development of a deficiency of these micronutrients. Data on vitamin sufficiency of patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) are needed to develop measures to improve it. The aim of the research was to compare vitamin status of patients with T2DM without DN and those with T2DM complicated by nephropathy by assessing vitamin blood level and urinary excretion. Material and methods. In a single-stage research, 57 patients with T2DM and concomitant obesity (14 men, 43 women aged 42-75 years) have been examined. The 1st group included 26 patients with T2DM (7 men and 19 women, BMI 41.5±1.7 kg/m2) with glycated hemoglobin (HbA1c) - 8.0±1.4%, blood serum glucose level 8.1±0.6 mmol/l, glomerular filtration rate (GFR) - 86.7±3.0 ml/min per 1.73 m2, microalbuminuria - 18.0±2.0 mg/day. The 2nd group included 31 patients with T2DM complicated by DN (7 men and 24 women, BMI 42.5±1.3 kg/m2), with an HbA1c level of 6.4±0.2%, blood serum glucose level 6.8±0.3 mmol/l, GFR - 62.8±2.7 ml/min per 1.73 m2, microalbuminuria - 59.5±22.5 mg/day. The determination of vitamins С (ascorbic acid), A (retinol), E (α- and γ-tocopherols), D [25(OH)D], B2 (riboflavin) and ß-carotene in blood serum and vitamins C (ascorbic acid), B1 (thiamine), B2 (riboflavin) and B6 (4-pyridoxic acid) in the morning portion of urine collected on an empty stomach within 40-120 min was carried out. The vitamin status was assessed based on the concentration of vitamins in blood serum and urinary excretion relative to the lower limit of the norm, as well as using the criteria for the optimal supply and 2 molar ratios. Results. Compared to patients with T2DM without nephropathy, patients with DN were better provided with vitamins B2, A and ß-carotene: vitamin B2 deficiency was found 3.2 fold less often (in 9.7%), ß-carotene - 1.8 fold less often (in 35.5%), nonoptimal retinol level occurred twice less often (in 41.9%). At the same time, serum α-tocopherol level below the optimal level was found in 67.7% of individuals versus 50% among patients with T2DM without nephropathy, with a significantly reduced urinary excretion of vitamins B1 and B2. With the exception of one man, the rest of the DN patients had a deficiency or lack of vitamin D. The characteristic features of the vitamin status of patients in both groups were the complete absence of individuals who were simultaneously optimally provided with all the studied vitamins and ß-carotene (when assessing the vitamin status using both the absolute serum vitamer levels and 2 additional molar ratios), and a high frequency of detection of several simultaneously non-optimal vitamin status indicators. A negative correlation was found between blood serum level of ß-carotene and glycemia (ρ=-0.359, p=0.006), as well as GFR (ρ=-0.289, р=0.029) and positive with high-density lipoprotein cholesterol (ρ=0.423, р=0.001), that indicated the need to increase this antioxidant blood level in patients with T2DM. The presence of a negative correlation between the concentration ratio of vitamins C and E and glucosuria (ρ=-0.288, p=0.033) and postprandial glycemia (ρ=-0.313, p=0.031) indicated the need to maintain it at an optimal level. Conclusion. For patients with T2DM and concomitant obesity, vitamin D and ß-carotene turned out to be the most problematic, since their reduced levels are detected more often than other vitamins. In addition to the optimal blood level of vitamins C and E, it is extremely important for them to maintain the blood molar ratio of ascorbic acid and α-tocopherol at an optimal level. The purposefully development of specialized vitamin complexes containing effective doses is necessary for patients with DN.

[Influence of multiple insufficiency of vitamin D and B group vitamins, calcium and magnesium in the diet of rats on micronutrient sufficiency and plasma biochemical indicators].

The lack of vitamins D, B group, calcium and magnesium is common for the diet of the Russian population. It has been previously demonstrated that that the elimination of B vitamin deficiency is a necessary condition for the implementation of vitamin D biological functions. The aim of the research was to assess the effect of a combined deficiency of vitamins D and B group, calcium and magnesium in the diet of rats on biomarkers of micronutrient sufficiency and plasma biochemical indicators. Material amd methods. Male Wistar rats with an initial body weight of 66±1 g were randomly assigned to one of five groups. The rats of the 1st group (Control) were fed a standard semi-synthetic diet (SD) for 28 days. The combined deficit of vitamins D and B group, calcium and magnesium in rats of four experimental groups was caused by a 5-fold decrease in their content in the vitamin mixture and 2-fold decrease in their content in mineral mixture of the SD for 23 days. Over the next 5 days, the rats of 2nd group (+В+D+Ca+Mg) were fed a diet replenished for all missing vitamins and minerals, the rats of 3rd group (-В+D+Ca+Mg) were fed a diet with continued deficiency of B group vitamins, the rats of the 4th group (+В+D-Ca-Mg) were fed a diet with continued lack of calcium and magnesium, the diet of the 5th group (-B-D-Ca-Mg) was not replenished. Vitamins B1 and B2 in lyophilized liver and brain and urine, riboflavin in plasma and 4-pyridoxic acid in urine were determined by fluorimetric methods, 25(OH)D in plasma was determined by ELISA, the level of vitamins A and E in blood plasma and lyophilized liver, of vitamin E in whole brain - by HPLC. Biochemical parameters of blood plasma were determined using a biochemical analyzer. Results. In rats of the 5th group (-B-D-Ca-Mg), there were 3.4-fold increase (p<0.05) in iron plasma level, 1.7-fold elevation (p<0.10) in alkaline phosphatase activity, and 1.8-fold decrease (p<0.05) in alanine aminotransferase (ALT) activity on the background of the increase in α-tocopherol blood plasma level by 26.7% (p<0.05) and liver content by 2.0 fold (p<0.05) relative to the indicators in animals who hadn't passed the deficiency of micronutrients (Control) and / or from the 2nd group (+B+D+Ca+Mg). The lack of B group vitamins in the diet, which persisted during the correction of vitamin D, calcium and magnesium deficiency in rats of the 3rd group (-B+D+Ca+Mg), inhibited the recovery of diagnostically significant biochemical parameters of blood plasma (namely, an increased level of glucose, iron, triglycerides, cholesterol, α-tocopherol, increased alkaline phosphatase activity and reduced ALT activity) to the level in animals of the control group and/or rats fed the diet replenished for all missing micronutrients (+B+D+Ca+Mg). Conclusion. Combined deficiency of several micronutrients led to changes in biochemical blood parameters. Reduced intake of calcium and magnesium during the correction of the lack of vitamins D and B group in the diet can have a negative impact on vitamin B2 status. Even under normal dietary vitamin E intake the combined deficiency of several other micronutrients affected the metabolism of this vitamin (increased levels of vitamin E in the liver and blood plasma of animals). Chronic combined alimentary deficit of B vitamins, calcium and magnesium, which is characteristic in the diet of the Russian population, reduces vitamin D bioavailability, which justifies the expediency of using vitamin-mineral complexes.

[Efficiency of vitamin D deficit correction depending on rats' supply with B vitamins].

Despite the presence of combined deficiency of vitamins D and group B among the population of Russia, the intake of cholecalciferol is often recommended without correcting the supply with B group vitamins, which are involved in ensuring the biological functions of vitamin D. The aim of the study was to compare the effectiveness of vitamin D deficit correction by replenishing its content in the diet to an adequate level without eliminating the deficit of B vitamins and by restoring vitamin D level in combination with B vitamins. Material and methods. The experiment was carried out on male Wistar rats (n=33) with an initial body weight of 69.5±0.8 g. Combined deficit of vitamins D and B group in rats (n=24) was caused by a 5-fold decrease in their content in the vitamin mixture of a semi-synthetic diet for 23 days. Over the next 7 days, in order to correct vitamin deficiency, 12 rats (group «-B+D¼) were fed a diet, replenished up to 100% for vitamin D with continued deficiency of B group vitamins, and 12 rats (group «+B+D¼) were fed a diet replenished for all missing vitamins. Animals of the control group (n=9) received a full semi-synthetic diet during the entire experiment. The concentration of vitamins A and E in blood plasma and lyophilized liver and whole brain was determined by HPLC, vitamins B1 and B2 in the liver, brain and urine, riboflavin in plasma and 4-pyridoxic acid in urine - by fluorimetric methods, 25(OH)D in blood plasma was determined by ELISA. The content of calcium, magnesium, iron, manganese, zinc and copper in freeze-dried liver and brain was determined by atomic absorption method, biochemical parameters of blood and urine were determined using a biochemical analyzer. Results. The only vitamin D addition to the feed with a persisting deficiency of B vitamins did not restore the concentration of 25(OH)D and osteocalcin to the level in control animals sufficiently provided with all vitamins. In animals of the "-B+D" group, 25(OH)D plasma level was reduced by 17.3% (p<0.10), osteocalcin - by 11.7% (p<0.05), the activity of aspartate aminotransferase was 1.5 fold less, alanine aminotransferase - 2.3 fold (p<0.05), lactate dehydrogenase - by 14.9% (p<0.10), while the concentration of iron exceeded 2.7 times, glucose - by 15.0%, calcium - by 8.0%, creatinine - by 8.7% (p<0.05), urea - by 32.1%, direct bilirubin - by 24.2% (p<0.10 ) compared with corresponding indicator in rats of the control group. The level of cholesterol and HDL cholesterol was 14.7% and 15.9% higher (p<0.10) than in animals of the «+B+D¼ group. Conclusions. Deficiency of B vitamins inhibits the restoration of adequate supply with vitamin D. In the presence of a lack of B vitamins in rats, vitamin D deficit and its consequences cannot be completely eliminated. Adequate supply with vitamins D and B group are synergistic factors in maintaining the level of glucose, cholesterol in blood plasma and other diagnostically significant parameters.

[Biological value of fruits and berries of Russian production].

Fruits and berries are the most important sources of a wide range of biologically active substances, including vitamin C, carotenoids, flavonoids, anthocyanins. In order to replenish and update data on the content of food and biologically active substances in the tables of the chemical composition of food products, a study of the content of mono- and disaccharides, dietary fiber was carried out; vitamins C, B1, B2 and E, minerals and trace elements; flavonoids (in terms of rutin), anthocyanins; organic and hydroxycinnamic acids, stilbenoids in various varieties of 16 fruit and berry crops. Material and methods. The material for the study was the fruits of promising varieties and selected forms of pome fruit (apple, pear), stone fruit (cherry, plum, apricot), berry (garden strawberry, raspberry, black currant, red currant, gooseberry), non-traditional crops (actinidia, honeysuckle, cornelian cherry, viburnum, sea buckthorn, rosehip) - a total of 208 samples grown at the I.V. Michurin Federal Scientific Center. The B vitamins were determined by the fluorometric method, and vitamin E, organic and hydroxycinnamic acids, carbohydrates, and stilbenoids were determined by HPLC. The amount of anthocyanin pigments was determined by pH differential spectrophotometry, dietary fiber - by enzymatic-gravimetric method, flavonoids - spectrophotometrically. Results and discussion. The main carbohydrate of apricot is sucrose, black currants, cherries, raspberries and honeysuckle contain mainly fructose and glucose. Raspberries and currants are high in fiber. Comparison of the obtained data on the content of vitamins B1, B2, E, flavonoids and anthocyanins in the studied population of varieties in comparison with the published data of tables of the chemical composition of food products in the USA and Russia was carried out. By the content of vitamin C in descending order, the fruits are arranged in a row: black currant > sea buckthorn > honeysuckle > strawberry > red currant > viburnum > gooseberry > raspberry > apple. Berries, making a significant contribution to providing the body with vitamin C, are not an essential source of vitamins B and E. The inclusion of 100 g of fresh fruit in the diet provides about 10% of the recommended dietary intake for potassium (apricot, gooseberry, cherry and black currant), magnesium (apple, cherry, strawberry) and dietary fiber. Honeysuckle and black currant are high in anthocyanins; consumption of 100 g of these berries will ensure adequate intake of these micronutrients. Some varieties of strawberries, apples and pears are rich in hydroxycinnamic acids. The data obtained can be used to refine the indicators in the existing tables of the chemical composition of food products. Conclusion. The obtained data on the composition of fruit and berry products will make it possible to more correctly calculate the nutritional value of rations using questionnaire-survey methods. Combined analysis of the composition of biologically active substances in berries and fruits makes it possible to more reasonably make the choice of a particular product in the dietary correction of the ration of healthy and sick people.

[Biomarkers of vitamin status in obese school children].

Inadequate intake of vitamins, noted in children with obesity, reduces the immune system activity, contributes to the metabolic disorders aggravation and may result in comorbidity. The aim of the work was to study sufficiency with vitamins and carotenoids of children with obesity. Material and methods. Examination of vitamin D, B2, C, A, E and ß-carotene status in 50 children (male 36.0%) aged 11-17 years [median (Me) - 14 years] with obesity [Z-score body mass index (BMI) >=2.0, Ме=2.86] by determining serum biomarkers has been conducted. Results and discussion. All of the children had an adequate supply with vitamin C (ascorbic acid level >0.4 mg/dL). Low vitamin A status (retinol <30 µg/dl) was revealed in 8% children. Deficiency of vitamin D [25(OH)D<20 ng/ml], vitamin B2 (riboflavin <5 ng/ml) and ß-carotene (<10 µg/dl) was detected in 62.0, 38.8 and 74.0% of obese children. The percentage of persons with reduced vitamin E serum level (<0.8 mg/dl) was amounted 54.0%. A severe vitamin D deficit (<10 ng/ml) has been detected in 24.0% of children with Z-score BMI >=2.86 (median value) and has not been observed in children with lower body weight, whose serum ß-carotene median was 1.5 fold higher (p<0.05). No one was adequately supplied with all 5 studied vitamins and ß-carotene. The combined deficiency of 3 or more vitamins took place in 54.0% of obese children. Synchronously suboptimal serum level of ascorbic acid (<50 µmol/l), ß-carotene (<0.4 µmol/l) and α-tocopherol/cholesterol ratio (<5.0 µmol/mmol) which is a cardiovascular disease risk factor, has been found in 28.0% of children. BMI was inversely associated with 25(OH)D serum concentration (ρ=-0.313, р=0.027). There was a pronounced negative correlation between serum level of ß-carotene and atherogenic LDL cholesterol (ρ=-0.514, p<0.001). Conclusion. The prevalence of combined vitamin D, tocopherol and carotenoids' inadequacy in obese children indicates the importance of vitamin status correction to reduce the risk of metabolic syndrome.

[Nutrient value of fruit in promising strawberry varieties].

One of the current areas in research of fruit and berry crops is the study of their nutritional value and micronutrient composition. Valuable chemical composition of the strawberry determines a wide spectrum of its utilization not only as fresh fruit, but also as a raw material for food industry. Breeding requirements for contemporary strawberry varieties together with yield, large-fruit, important taste and dietary qualities of fruit provide for higher content of biologic active substances. The aim of the research was an integrated assessment of strawberry fruit for content of nutrients and bioactive compounds, as well as mineral elements, and its antioxidant activity. Material and methods. The objects of investigation were berries of 5 strawberry varieties bred in the I.V. Michurin Scientific Centre (Lakomaya, Prazdnichnaya, Privlekatelnaya, Urozhaynaya CGL, Feyerverk) and 9 foreign varieties (Vima Zanta, Dukat, Zefir, Kama, Maryshka, Red Gauntlet, Festivalnaya romashka, Honey, Elsanta) which are promising for cultivation in the Black Soil Region of Russia. The content of soluble solids was determined by the refractometric method, sugars - by Bertrand's method, pectins - by the volumetric method, anthocyanins - by pH-differential spectrophotometry. Total content of antioxidants was defined by amperometric method with recalculation per quercetin. Determination of vitamin B1 was carried out using the fluorometric thiochrome method, vitamin B2 - by fluorometric titration with riboflavin-binding apoprotein after acid-enzymatic hydrolysis, ascorbic acid, vitamin E (tocopherols), niacin, organic and hydroxycinnamic acids - by HPLC, flavonols - spectrophotometrically, minerals and trace elements - by atomic absorption method. Results and discussion. A significant variation in the chemical composition indices depending on the varietal characteristics was found. Strawberry fruit accumulated 8.5-12.0% soluble solids, 5.9-8.7% sugars, 1.5-2.1% of fibre, 0.78-1.12% pectin substances, 0.89-1.45% organic acid; 100 g contain 33.5-48.2 mg vitamin C, 18.3-108.5 mg anthocyanins, 0.024-0.041 mg vitamin B1, 0.012-0.029 mg vitamin B2, 0.10-0.26 mg niacin, 0.26-0.60 mg TE vitamin E, 102-270 mg potassium, 0.15-0.95 mg iron; total antioxidant activity ranged within 180.8-350.0 mg/100 g. High level of anthocyan accumulation (over 80.0 mg/100 g) was observed in Privlekatelnaya, Lakomaya and Feyerverk strawberry varieties. Urozhaynaya CGL, Privlekatelnaya and Lakomaya varieties were characterized by dessert taste. According to the results of the studies Privlekatelnaya variety stood out because of the high complex accumulation of vitamin C, anthocyanins, and high total antioxidant activity. These varieties are recommended for both fresh use and for freezing, as well as for production of functional foods. Conclusion. The obtained data are of interest for further inclusion in the Tables of the chemical composition of Russian food products.

[Consumption of carbohydratecontaining beverages and their contribution to the total calorie content of the diet].

The article presents data on the frequency of consumption of carbohydrate-containing sweet carbonated drinks by the population of the Russian Federation and their contribution to the overall caloric intake of the diet. Questioning 11 850 people of different ages (from 12 to 60 years) and sex in all eight Federal Districts of Russia has been conducted. The frequency of food consumption has been studied, and in parallel dietary intake has been assessed using 24-hour recall method. The survey showed a fairly low frequency of consumption of sweet carbonated beverages and no significant differences in the frequency of their consumption by the population of various federal districts of Russia. With a certain frequency from 55.5 to 67.3% of the population consumed sweet carbonated drinks, while 18.1-20.9% of the respondents did not consume them more often 1-3 times a month, and 1.3% of the surveyed (from 0.3% in the North- West to 3.9% in the Southern Federal District) - 2 times a day or more often. Analysis of the data obtained showed that the contribution of the carbohydrate component contained in sweet carbonated beverages, even when consumed frequently (5-6 times a week) did not exceed 3.71% of the total diet calorie intake and not more than 7.1% of the caloric value of carbohydrates' intake.

[Content of some vitamins in food ration and blood serum of professional athletes].

The aim of the work was a comparative assessment of the vitamin status of athletes specializing in different kinds of sport (bobsleigh, dispersing and pilots, biathlon, bullet shooting) by means of assessment of the content of vitamins in the diet and blood serum. 159 professional athletes of both sexes were examined in the pre-competition period of the sport activity. The average age of the surveyed 92 men was 21.7±0.8 years, 67 women - 23.1±1.5 years. The actual data on the intake of some vitamins with the main and supplementary diet and blood serum have been presented. The basic diet of athletes didn't provide adequate intake of vitamins. The most pronounced deficiency of B vitamins and vitamin C in the basic diet was noted in female athletes specializing in bobsleigh. Only enrichment of the basic diet with specialized products for athletes and dietary supplements allowed sportsmen to increase their vitamin intake to the recommended level. At the same time, the intake of vitamins В1 and В2 with supplements in a number of athletes exceeded the upper permissible level of their consumption as a part of dietary supplements and specialized food products. The concentration of vitamins C and A in the blood serum exceeded the lower limit of the physiological norm in all athletes. At the same time, in 15.6 and 35.9% of the people, the concentration of these vitamins exceeded the upper limit of the norm. In 17.4% of the examined, a lack of vitamin E was identified, while an increased tocopherol concentration was found in 22.3% of athletes. Comparison of data on the vitamin consumption and their blood level made it possible to conclude that, in order to maintain the optimal vitamin status of the athlete's organism, it was inappropriate to use excessive doses of vitamins C (>200-300 mg/day), E (>50 mg TE/day) and A (>1500 µg RE/day). The unreasonableness of using in the diet of athletes excessively high doses of antioxidant vitamins, the increased demand for B vitamins and the appropriateness of correlating the need for B vitamins with the energy value of the diet have been discussed.

[Effect of B-vitamin deficiency on biochemical, immunologic markers and trace element status of rats and mice of various lines].

Biochemical, vitamin, trace element and immunological changes were searched for the combined nutritional deficiency of vitamins B1, B2, B6 on in vivo models in rats and mice. Female rats of Wistar (W) strain and hybrids of the 1st generation of Dark Aguti and Wistar (DA x W) strains, female mice of BALB/c strain and DBCB tetrahybrids were used in experiment. Animals received for 35 days a balanced diet (control) according to AIN-93 or a similar diet with the exception of vitamins B1, B2, B6 (experimental groups). The content of vitamins B1, B2 in liver, riboflavin blood plasma level and urinary excretion of thiamine, riboflavin and 4-pyridoxic acid were determined, as well as in rats: blood and liver content of α-tocopherol and retinol, blood biochemical indices of lipid and nitrogen metabolism, activity of cytochrome P isoforms-450 (CYP) in liver; in mice: the circulating levels of pro- and anti-inflammatory cytokines of blood plasma, in animals of both species - the content of essential and toxic elements in the kidneys. DAxW rats compared to W and DBCB mice compared to BALB/c were more sensitive to the development of B-vitamin deficiency judging by the B-vitamin status indicators. In the rats of the experimental groups, there were signs of a deterioration in blood and liver levels of vitamin E, multidirectional shifts in vitamin A sufficiency, increased activity of the CYP3A isoform (6ß-TG), a decrease in triglycerides, total protein and albumin fraction levels with an increase in urea level. Manifestation degree of these effects depended on the choice of the animal's line. In mice, the B-vitamin deficiency was characterized by an increase in the levels of proinflammatory cytokines TNF-α, IL-10, IL-Ιß, IL-6 and a decrease in IFN-γ and IL-17A. The content of magnesium, copper, zinc, chromium and silver was lowered, of cesium - was increased in the kidneys of the rats of the experimental groups. In mice, B-vitamin deficiency resulted in diminishment of magnesium, copper, zinc, chromium, selenium, cadmium and lead content, excess accumulation of cobalt and cesium. Some of these biomarkers are supposed to be used in pre-clinical evaluation of the effectiveness of new vitamin complexes, specialized foods and dietary supplements, as well as studies of interactions of various vitamins.

[Vitamin status of adult population of the Russian Federation: 1987-2017].

In a review in order to characterize the dynamics of vitamin status for the period from 1987 to the present, the results of 16 surveys (conducted in 2015-2017) of the sufficiency with vitamins C, A, E, B2 and B6 of adult men and women of working age (about 1200 people) living in different regions of the Russian Federation, were compared with the frequency of vitamin insufficiency among the population in the previous period. The statistically significant improvement in the population's supply with vitamin C in the previous decade continued in 2015-2017. The deficit of this vitamin practically ceased to occur. Reduced blood serum levels of vitamin A were rare (except for patients with tuberculosis, the indigenous inhabitants of an inaccessible village beyond the Arctic region, and pregnant women, especially in the third trimester). In comparison with the previous period, a fairly rare occurrence of vitamin E deficiency persisted. Vitamin B2 deficiency was still detected in a significant number of subjects (25-75th percentile was at the level of 30-50%) and was encountered approximately at the same frequency as in the previous period. The lack of B vitamins in the adult population was still much more common than the deficiency of vitamins A, E and C. The incidence of the combined deficiency of three or more vitamins (including, in addition to vitamins C, A, E, B2 and ß-carotene, vitamins D, В6, В12, folates) currently ranged from 5 to 39%. In this same range was the frequency of observation of persons sufficiently supplied with all studied vitamins. To improve the vitamin supply of the population, the urgent need for legislative consolidation and/or adoption of normative acts regulating compulsory enrichment of food products of mass consumption (bread and milk) with vitamins D and B group has arisen.

[Comparative evaluation of vitamin status and biochemical markers of metabolic syndrome on the models of rodents receiving rations with high quotas of different sugars].

Metabolic syndrome (MS) is one of the leading causes of non-infectious pathology among the population of developed countries. It is necessary to have experimental in vivo models of MS for pre-clinical testing of new approaches to its dietary therapy. The purpose of the study was a comparative analysis of functional, biochemical and vitamin markers that characterize the effect of diets with different composition of simple carbohydrates (sugars) on female Wistar rats and female C57Black/6J mice. Animals of each species (n=80) were divided into 5 groups of equal numbers. The animals of the 1st (control) group received a balanced semi-synthetic diet, and the animals of groups from the 2nd to the 5th - the same diet and 30% solutions of sugars - glucose (Gl), fructose (Fr), equimolar mixture Gl and Fr and sucrose instead of water, in the regime of free access for up to 133 days. Measured values included blood pressure, mass of internals, biochemical parameters of blood plasma, the activity of CYP1A1, CYP1A2, CYP2B1, CYP3A and glutathione transferase (GT) in liver, glutathione peroxidase (GP) in erythrocytes, the content of vitamins A and E in blood plasma and in liver, the level of vitamins B1 and B2 and nicotinamide coenzymes in liver. Interspecific differences in the response to sugars manifested in a decrease in the solid diet consumption in mice (in contrast to rats), so that the total consumed energy value in experimental groups of mice did not differ systematically from control, and the weight gain was reduced. Liver was the most sensitive organ to addition of sugars in both rats and mice with mass significantly increasing by the 2nd and the 4th months of the experiment. Hyperglycemia and triglyceridemia were the most noticeable in rats receiving Fr. The concentration of phosphorus increased significantly in blood plasma of all rats groups that received sugars. In rats there was a decrease in the activity of CYP1A1 and CYP1A2 in groups 3 and 5, the activity of CYP2B1 in groups 2 and 5, the increase in HT activity in groups 2, 4 and 5, and GP in group 3 at 56th day of experiment. There was a significant decrease in this index in group 3 at the 56th and the 133rd days of the experiment, and in groups 4 and 5 - at the 56th day. Plasma tocopherol to triglycerides ratio decreased in rats of group 3 at the 56th and 133rd days, groups 4 и 5 - at 56th day, which indicated the decrease of vitamin E safety. Sugars consumption suppressed retinol palmitate accumulation in the liver of rats and mice, and alpha-tocopherol in mice. It was concluded that Fr had the greatest effect on the studied indicators of the organism, and the rats showed the most significant similarity with the clinical picture of MS.

[Evaluation of vitamin status of workers of oil-processing enterprises (Samara Region) according to the data on vitamin consumption and blood serum level].

Vitamin status of 77 employees of oil refineries (39 men and 38 women aged 22 to 62 years, body mass index - 25.0±4.7 kg/m2) has been assessed in autumn. The sufficiency with vitamins A, E, D, B2, B12, folate and beta-carotene was evaluated by determination in blood plasma, daily intake of vitamins B1, B2, niacin, C, A and betacarotene was calculated by frequency of food consumption during previous month. All surveyed were sufficiently supplied with vitamins A, B12 and folate (reduced level was detected in 0-2.6%). The content of tocopherols referred to triglycerides was reduced in 33% of the workers, in men it was 2 fold more likely (p<0.05) than in women (43.6 vs 21.1%). Vitamin D insufficiency took place in 23.4% of individuals, vitamin B2 and beta-carotene - in 44.2%. A reduced blood plasma content of one vitamin was detected in 39.0% of the surveyed, while two vitamins - in 24.7% persons, 2.2 fold more often (p<0.05) in men than in women. Multivitamin insufficiency was detected in 10.4% of workers. Reduced blood plasma level of at least one vitamin-antioxidant was detected in 46.8% (in 61.5% of men and 31.6% of women, p<0.05). 26.0% of surveyed were provided with all 6 vitamins and beta-carotene. Reduced relative to RDA daily intake of antioxidant vitamins (ascorbic acid and beta-carotene) was observed in 64.9 and 100% of individuals, B group vitamins (niacin, B2 and B1) - in 48.1-64.9%, vitamin A - in 42.9%.

[Vitamin status of rural residents, living in Russian Arctic].

The aim of this cross-sectional observational study was to estimate vitamin D, B2, A, E, ß-carotene (BC) status in rural residents, living in Russian Arctic (Yamal-Nenets Autonomous Area). 216 healthy adults (166 women, 50 men, 45.4±0.8 years old; BMI 27.5±0.5 kg/m2), 76% aboriginal ethnicity and 24% non-aboriginals subjects have been surveyed in spring 2016. Nenets were 72% among the surveyed, Russians - 14%, other ethnic groups - 14%. A total of 69 and 78% of subjects had 25(OH)D and BC blood serum concentrations less than the recommended target threshold of 30 ng/ml and 20 µg/dL respectively. Deficiency of vitamins B2, A and E, when blood serum concentrations of riboflavin <5 ng/ml, retinol <30 µg/dL and tocopherols <0.8 mg/dL, were found in 34, 15 and 13% of participants, respectively. The indigenous population was better supplied with vitamins D and B2. The lack of these vitamins was detected 1.3 and 1.8 fold less often (p<0.05) than in the non-aboriginals; whereas non-aboriginals were better provided with vitamin A and BC: the deficiency of these micronutrients was detected 3.1 and 1.8 fold less often (p<0.05) than in the inhabitants. In general, only 2.4% of those surveyed were sufficiently supplied with all 4 studied vitamins and BC. The frequency of deficit of one or two vitamins was revealed in 62.2%, combined deficiency of 3 or more vitamins was detected in 35.4%. There were no statistically significant differences in the incidence of combined multivitamin deficiencies among the indigenous and non-aboriginals. High incidence of vitamin A deficiency in the indigenous female population (21%) along with insufficiency of vitamin B2 in female non-aboriginals (48%), the lack of vitamin E in men (22%) and vitamin D and BC in 70-78% of the surveyed dictate the need for targeted enrichment of the diet of people living in extreme conditions of the Russian Arctic with multivitamin complexes.

[The study of the association between rs2228570 polymorphism of VDR gene and vitamin D blood serum concentration in the inhabitants of the Russian Arctic].

Genetic factor plays a significant role in nutrient deficiency development, including vitamins, by present time the association between several genetic polymorphisms and vitamin deficiency in the different regions of the world has been established. The aim of this study was to evaluate the possible association between VDR FokI polymorphism and vitamin D sufficiency in the population of the Yamal-Nenets Autonomous District of the Russian Federation. The group of participants included 172 people, among them 133 women and 39 men aged 20 to 75 years old. Genomic DNA was extracted from blood and genotyped for the single nucleotide polymorphism (SNP) of FokI T/C: (rs2228570) using allele-specific amplification, results were detected in real time using TaqManprobes complementary DNA polymorphic sites. The concentration of 25-hydroxyvitamin D [25(OH)D] was measured by ELISA. The decreased level of 25(OH)D in blood serum (<20 ng/ml) occurred in 38.2% of the population surveyed, and 25(OH)D blood level in the alien population of the region was significantly lower than that in the indigenous population. Genetic peculiarities of the inhabitants of the Arctic zone were identified by comparison with the inhabitants of the European part of the Russian Federation. Allele C frequency of VDR rs2228570 polymorphism in the alien population was 71.1%, higher than in indigenous population (50.0%) while in the inhabitants of the European part of Russia it was 57.8%. Vitamin D blood level was statistically significantly lower in all homozygous C allele carriers than in genotype TT carriers, and vitamin D deficit frequency was 2.3 fold higher (48.4 vs. 21.1%, p<0.05). In the group of indigenous people of this region vitamin D levels in carriers of CC and CT genotype were also significantly lower than that of TT genotype carriers. The incidence of vitamin D deficiency in homozygous carriers of the allele C (45.5%) was 5.5 fold higher than among TT genotype carriers (p<0.01), and 1.6 fold higher than that in CT genotype carriers (p>0.05). Thus, the association between C allele presence of rs2228570 polymorphism of VDR gene and a deficiency of vitamin D (reduced levels of 25 (OH)D in blood serum) has been revealed.

[Micronutrient status of population of the Russian Federation and possibility of its correction. State of the problem].

Vitamin status of the working population (about 950 subjects) from Moscow region, Samara, Nizhny Novgorod, Arkhangelsk, Yamalo-Nenetsky Avtonomny Okrug has been evaluated in 2015-2016. The lack of vitamin D assessed by means of blood serum level determination was detected in 57.5% of the adults, B vitamins - in 12.6-34.5%, vitamins A and E - in 5.3-10.8%, carotene - in 67.3%. Multivitamin insufficiency (the lack of 3 or more vitamins) was found in 22-38% of adults. Micronutrient fortification of foods of mass consumption is a promising way to improve vitamin status of the population. The needs for vitamins in medical, food industry and agriculture are satisfied only by imports. Calculation of the quantity of imported vitamins substances, carried out on the basis of databases of the Federal Customs Service of Russia, showed that import volume of vitamins increased and amounted to 9920 tons (125 980 000 dollars) in 2016. The estimated total demand of food industry in vitamins (substances) for the production of vitamin-mineral supplements (at the rate of 1-month course per person per year), the inclusion of vitamin and mineral supplements in health nutrition in hospitals and the production of fortified foodstuffs (at the rate of 24 kg of flour per year per one person and milk - 50 kg/year per person) was about 2.5 thousand tons per year. The absence of vitamin synthesis in the Russian Federation is a problem for increasing of nutritive value and quality of food products. The urgent need to revive domestic production (synthesis) of vitamin substances has appeared. The use of iodized salt instead of noniodized salt in bread and bakery production automatically converted it into enriched foods, which could improve the iodine sufficiency of the population.

[The analysis of domestic and international policy of food fortification with vitamins].

Fortification of food products of mass consumption with vitamins is a modern, most cost-effective, efficient and physiological way to improve the vitamin status of the population. Free or voluntary enrichment on the initiative of producers is used in the industrialized countries at low risk for inadequate population intake of micronutrients. Enrichment of products of mass consumption is almost always mandatory, legislative consolidated, while target enrichment of foods intended for different groups can be both mandatory and voluntary The criteria for the effectiveness of mandatory food fortification are an increase of certain vitamin consumption, reduce of the relative number of people with inadequate intake of certain micronutrients, improvement of micronutrient sufficiency (blood level), enhancement of biomarkers of some alimentar diseases, reduction of the frequency of congenital defects (neural tube defect). Assessment of risk/benefit ratio indicates safety of mandatory fortification of flour with B vitamins. In Russia, the regulatory framework for food fortification (enrichment levels, forms of vitamins) has been yet laborated. But initiative enrichment, held in Russia, does not give the desired result. An urgent need for legislative mandatory fortification of products consumed by the majority of the population (bread, milk) with B vitamins (the lack of which is the most frequently detected in the population of Russia) arose in a lack of knowledge of the population about the benefits of fortified foods and lack of preference in the selection of such products.

Influence of nanosized amorphous silica on assimilation of vitamins B1, B2 and B6 in rats.

Amorphous silica (SiO2) in the form of nanoparticles (NPs) is widely used as a food additive E551 in many enriched foods and food supplements. The aim of this study was to evaluate the effect of oral administration of SiO2 NPs on assimilation and metabolism of vitamins B1, B2 and B6 in laboratory rats. Amorphous SiO2 «Orisil-300 ®¼ was used with the size of the primary NPs 20-60 nm according to the electronic, atomic force microscopy and dynamic light scattering. The experiment was conducted on 8 groups of growing male Wistar rats (with initial body weight 70-80g) number, respectively, 7, 7, 10, 10, 12, 12, 14 and 16 animals. Animals of the 1st, 3rd, 4th and 5th groups received through­out the experiment balanced semi-synthetic diet. Animals of the 2nd group received a diet depleted of vitamins B1, B2 and B6 until day 21; animals of the 6th, 7th and 8th groups -the same diet from the 1st to the 21th day, and then, before the closure of the experiment, the diet provided with the indicated B vitamins at 100% of normal level. From day 22 of experiment and until the end at day 29 the animals of the 3rd and 6th groups received deionized water (placebo) through intragastric gavage; rat of the 4th and 7th groups -aqueous suspension of SiO2 dose of 1 mg/kg body weight /day, and the 5th and 8th group -100 mg/kg/day. Urinary excretion of thiamine, riboflavin, 4-pyridoxilic acid and liver and brain content of vitamins B1 and B2 (after acid and enzyme hydrolysis) were deter­mined by fluorimetric methods. It was found that rats in group 2 lagged in weight gain at day 21 significantly compared to group 1, and developed a marked deficiency of vitamins B1, B2 and B6 according to studied safety parameters. In groups from 6 to 8 at day 29 par­tial recovery was achieved in vitamin status. Administration of SiO2 to animal of groups 4 and 5, with normal consumption of B vitamins, had no significant effect on any param­eters of vitamin status in comparison to group 3. However, intragastric administration of SiO2 led in animals of groups 7 and 8 to an increase in the urinary excretion of vitamins B1 and B2 and lowering of their content in liver as compared to group 6. Administration of SiO2 had no effect on indices of vitamin B6 sufficiency. Possible reasons are discussed for the adverse lowering impact of SiO2 NPs on the availability of vitamins B1 and B2 and their increased clearance from the body.

[Vitamin status of citizens from Moscow Region].

Evaluation of vitamin status in healthy individuals (68 men and 70 women) aged from 18 to 60 years (median - 37 years), residents of Moscow and the Moscow region has been performed by means of determination of vitamin C, A, E, B2, B12 and folic acid level in blood serum. The nutrition was investigated by questionnaire method on frequency of food consumption. Both diet of men and women had excessive fat content (41.7 and 42.7% of total calories), saturated fatty acids (14.1 and 13.6%), added sugars (11.1 and 11.0%), sodium, and had lack of dietary fiber (2.5-fold reduced level comparing with RDA). Daily intake of vitamin B1 was 1.37±0.04 mg for men and 1.06±0.07 mg for women, vitamin B2 - respectively 1.72±0.06 and 1.62±0.07 mg, niacin - 18.5±0.72 and 14.8±0.88 mg and did not reach the optimal level. All persons were sufficiently supplied with vitamins A, C, E and B12: mean and median of blood serum level of retinol, tocopherols, ascorbic acid and cobalamins were in the range of optimum values. The lack of vitamins A and B12 has not been found in any person. The frequency of vitamin C and E insufficiency was insignificant and amounted to 2 and 8% respectively. The lack of vitamin B2, and ß-carotene was most pronounced and took place in about a half of individuals. Only 34% of healthy people of working age were sufficiently supplied with all vitamins. A combined lack of two vitamins was detected in 26%, of three vitamins - in 8%. Women were better supplied with riboflavin and ß-carotene. The blood serum level of ß-carotene and vitamin E was significantly higher in individuals older than 30 years compared with persons of younger age. Individuals with overweight or obesity were worse supplied with ß-carotene and folate. A negative correlation was detected between the levels of serum folate and homocysteine concentration (r=-0.262, p<0.05). A positive correlation has been revealed between the concentration of folic acid and the level of HDL-C (r=0.356, p<0.01), and iron (r=0.378, p<0.05).