[To the 20th anniversary of the Chornobyl accident study of vitamin status and provision with micro- and macroelements of limited groups of people at different time periods since the accident at Chornobyl nuclear power plant].

Results of the study of the provision with vitamins and some micro- and macroelements of limited groups of people, who suffered from the accident at the Chornobyl nuclear power plant (ChNPP), which have been carried out by Ukrainian and Russian scientists during various periods after the accident, are generalized in the paper. Persons which participated in liquidation of the accident and lived during the accident in the territory, adjoining to Pripyat (the Kyiv region, town of Slavutich), people which worked at the object "Shelter" and ChNPP were involved in the inspection. It was noted, that in 1-4 years after the ChNPP accident in blood of liquidators the biochemical parameters displaying security of their organism by vitamins A and B1, remain lower in comparison with the same parameters in a group of relatively healthy persons which were not affected by the accident (control), that testifies to stable metabolic disturbance in the organism of people under irradiation influence. Selective inspection of the vitamin status of ChNPP and object "Shelter" personnel in 1992 has shown, that provision with vitamins C, B1, B2, B6 of the overwhelming majority of these people (67-91%) are much below the norm. Deficiency of vitamins C, B1, B6, folate and selenium is also revealed in an organism of 50-90% of women and children living in Slavutich. Deficit of vitamins in most of persons was characterized by polyhypovitaminoses, that is a combination of several group B vitamins deficiency at simultaneously low provision with selenium, and in a part of women and children--by low amount of iron. The results of long-term complex studies by groups of authors give evidence on importance and urgency of formulation and execution of International program on optimisation of nutrition, micronutrition status and health among population of affected areas in Ukraine, Bielorus' and Russia.

[To 20-years anniversary of Chernobyl catastrophe: an attempt to study the vitamin, calcium, iron and selenium status of children and adult population in Slavutich and to correct elicited deficiencies].

The article concisely illustrates the vitamin and mineral state of population of town of Slavutich, including personal of Chernobyl Nuclear Power Station, children of pre-school age and pregnancy women, studied in 1992. Vitamins and minerals deficiency in the main of C and B vitamins and selenium was revealed in all the studied groups. Appropriate measures were developed and introduced to eliminate the detected dusturbances; but however some unsolved problems remained. Taking into account the forthcoming 20th anniversary of Chernobyl disarter, the authors of the come back to considering the obtained data in hope to atlract attention of medical scientific and public to the remained unsolved problems of micronutrient deficiency.

[Phosphorus-calcium metabolism and dietetic correction of its disorders in chronic kidney diseases in children]. / Sostoianie fosforno-kal'tsievogo obmena i dieticheskaia korrektsiia ego narushenii pri khronicheskikh bolezniakh pochek u detei.

Ninety children with varying renal diseases were under observation. The investigations conducted have shown that disorders in phosphoric-calcium metabolism depend on the type, activity of chronic glomerulonephritis (CGN) and etiology of chronic renal insufficiency (CRI). Significant disorders in phosphoric-calcium metabolism were detected in patients with nephrotic and mixed types of CGN. Most manifest clinical and x-ray changes of the osseous system were observed in patients with CRI that developed as a result of the tubulointerstitial pathologic process. Low-phosphate diets with preset amounts of Ca and P were developed, composed of products with relatively low content of P, and of new dietetic products rich in Ca. The diets were used for correction of hyperphosphatemia in children with CGN and in those with CRI, simultaneously with drug therapy, to prevent or diminish disorders in phosphoric-calcium metabolism, and to reduce the risk of invalidism among children with chronic renal diseases.

[Comparative study of the toxicity of 1 alpha-hydroxyvitamin D3 and 24,25 (RS)-dihydroxyvitamin D3 in rats]. / Sravnitel'noe izuchenie toksichnosti 1 al'fa-oksivitimina D3 i 24,25 (RS)-dioksivitamina D3 u krys.

The toxic effects of 1 alpha (OH)D3 and 24,25 (OH)2D3 administered in doses of 0.25, 2.5 and 25 micrograms per animal a day were compared in rats weighing initially 230-260 g and fed an artificial diet containing 0.65 and 0.50% of Ca and P, respectively. After 5 days of administering different doses of 1 alpha (OH) D3 hypercalcemia and hyperphosphatemia developed whatever the dose, the animals' weight and density of the osseous tissue dropped starting with a dose of 2.5 micrograms, together with a high death rate and Ca accumulation by soft tissues at a dose of 25 micrograms per animal. Unlike 1 alpha (OH)D3, 24,25 (OH)2D3 did not exert any hypercalcemic or hyperphosphatemic action when given in a high dose (25 micrograms). On the contrary, it promote the decrease of the Ca and P blood levels. 24,25 (OH)2D3 did not bring about Ca accumulation by the organs or reduction of the osseous tissue density whatever the dose applied. In addition, the metabolite administered in a dose of 25 micrograms arrested the animals' growth. Thus, when given in comparable doses (the physiologic requirement of 1 alpha (OH)D3 and 24,25 (OH)2D3 for rats are 0.025 and 0.25 micrograms/day, respectively), 24,25 (OH)2D3 was at least one order of magnitude less active as regards its capacity to increase the Ca and P blood levels and to resorb the osseous tissue. The data obtained and the inhibitory effect on the growth of the 100-fold dose of 24,25 (OH)2D3 point to the feasibility of the short-term use of the metabolite in doses that do not exceed more than 10-fold the physiologic dose.

[Metabolism of 25-hydroxyvitamin D3 and its regulation in rats during hypokinesis]. / Metabolizm 25-oksivitamina D3 i ego reguliatsiia u krys pri gipokinezii.

The influence of short-(7 days) and long-term (28 days) hypokinesia on 25-hydroxyvitamin D3 metabolism was investigated in rats fed on a normal calcium (0.6%), normal phosphorus (0.6%), vitamin D-supplemented diet. The animals were given a single intraperitoneal dose of tritiated [26,27-3H]25(OH)D3 (200 pmol) eighteen hours before sacrifice. [3H]Labelled vitamin D3 metabolites were separated by high performance liquid chromatographic procedure, and their radioactivity levels in serum, kidney, intestinal mucosa and femoral bone were measured. Long-term hypokinesia resulted in decreased levels of [3H]1.25(OH)2D3 and increased levels of [3H]24.25(OH)2D3 in serum and kidney (3.15 +/- 0.62 vs. 4.33 +/- 0.41% and 5.34 +/- 0.69 vs. 3.76 +/- 0.29% for [3H]1.25(OH)2D3 and [3H]24.25(OH)2D3 in serum; 7.52 +/- 0.69 vs. 11.6 +/- 0.79% and 9.33 +/- 0.55 vs. 5.94 +/- 0.24% for those in kidney). The levels of [3H]1.25(OH)2D3 as well as of [3H] 24.25(OH)2D3 were decreased in intestinal mucosa and bone (21.5 +/- 1.46 vs. 30.1 +/- 3.04% and 7.30 +/- 0.58 vs. 9.18 +/- 0.78% for [3H]1.25(OH)2D3 and [3H]24.25(OH)2D3 in intestinal mucosa; 6.39 +/- 06.5 vs. 11.5 +/- 1.64% and 7.78 +/- 0.71 vs. 13.9 +/- 1.28% for those in bone). The data obtained suggest a suppressed synthesis of 1.25(OH)2D3 and enhanced production of 24.25(OH)2D3 in kidney as well as a diminished binding of 24.25(OH)2D3 in intestinal mucosa and bone in hypothetic rats. Possible causes of variations in biosynthesis of vitamin D3 active metabolites, and role of these variations in the disorders of calcium metabolism and bone state during hypokinesia are discussed.

[Characteristics of calcium-phosphorus metabolism and vitamin D allowance in the Far North]. / Osobennosti kal'tsii-fosfornogo obmena i obespechennost' vitamina D v usloviiakh Krainego Severa.

Examination of children aged 3 to 17 years and adult population including parturients living in Naryan-Mar and northern settlements of the Nenets national district revealed the reduced calcium and elevated phosphorus concentrations in the blood serum of the examinees as compared with respective parameters in analogous population groups living in the middle zone of Russia (Moscow and Kazan). These changes, particularly marked in winter and spring, are determined by national and local features of the diet poor in calcium and containing excess amount of phosphorus. The concentration of 25-hydroxyvitamin D in the blood serum of the population living in the Extreme North was 2 times lower than that in the population of the middle zone, constituting 15-20 and 30-40 ng/ml, respectively. The reason for a lower vitamin D supply in the North is insufficient insulation.

[Effect of excess phosphorus consumption on a phosphorus-calcium metabolism and bone tissue of rats under hypokinesia]. / Vliianie izbytochnogo potrebleniia fosfora na nekotorye storony fosforno-kal'tsievogo obmena i sostoianie kostnoi tkani krys pri gipokinezii.

The exposure of rats fed with the diet containing Ca : P = 1 : 0.5 - 1 : 3 to hypokinesia produced hypocalcemia, osteoporosis and increased renal calcinosis. The reduced phosphorus consumption (Ca : P = 1 : 0.5 - 1 : 1) prevented these disorders in the intact animals and increased bone density in the hypokinetic rats. The excessive phosphorus consumption caused hypocalcemia, hyperphosphatemia and slight osteoporosis in both intact and hypokinetic rats, with the changes being more pronounced in those latter. It is concluded that the diet with Ca : P = = 1 : 0,5-1 : 1 is optimal for hypokinetic rats.

[Role of 24,25-dihydroxycholecalciferol in bone mineralization under hypokinesia in the rat]. / Rol' 24,25-dioksikholekal'tsiferola v mineralizatsii kostnoi tkani krys pri gipokinezii.

24,25-Dihydroxycholecalciferol, an active D3 vitamin metabolite, at a dose of 1.25 microgram/day/animal prevents bone osteoporotic changes, effectively stimulating the diaphyseal and epiphyseal mineralization, and corrects hypocalcemia of hypokinetic rats. 24,25(OH)2D3 at the above dose does not increase nephrocalcinosis or does not produce the toxic effect as measured by body mass variations.