Introduction. The nutrition of primary school children does not always meet modern nutritional standards. The frequency of nutritional deficiencies, including calcium and vitamin D, among this age group remains unstudied. The aim of the study. To establish the characteristics of nutritional provision and the prevalence of nutrient deficiencies in the daily nutrition of primary school children, including calcium and vitamin D deficiencies and to propose methods of correction. Materials and methods. 5 consecutive stages of the study were conducted. At the first stage in 2019, the assessment of eating behavior in 190 children of grades 1-4 of two schools in the city of Lviv was conducted using a questionnaire. In the second stage, the features of the diet and ration and daily nutritional intake were determined using a special licensed program Dietplan 7 (UK). The analysis of daily nutrient intake was performed for 172 children. In the third stage, a study was conducted on the level of total, ionized calcium and 25-hydroxyvitamin D in the blood, and a study on the calcium content in the hair of 56 children with insufficient daily intake of calcium and / or vitamin D. In the fourth stage, 30 children with reduced levels of calcium in the hair were detected, differentiated correction measures were performed. To do this, the children were divided into two groups: the control group - 15 children whose deficiencies were corrected by diet modification, and the main group - 15 children - whose deficiencies were corrected by diet modification and the intake of calcium at a dose of 500.0 mg and vitamin D at a dose of 5.0 mg (200.0 IU) once a day for three months. In the fifth stage, to evaluate the effectiveness of treatment after three months of follow-up, all 30 children were re-analyzed for calcium content in the hair using atomic absorption spectrophotometry. Results. Appetite disturbance was observed in 28.9 % of schoolchildren, 17.4 % ate under duress, 14.3 % ate irregularly, 13.7% ate insufficient portions, 11.0 % were on different diets, many schoolchildren had eating disorders: ate before sleep (83.6 %), while watching TV (33.6 %). The diet was often unbalanced, children consumed insufficient fish (58.9 %), vegetables (43.2 %), dairy products (33.7 %), meat (26.8 %) Low calcium intake was observed in 50.6 % boys and 70.7 % of girls, vitamin D in 84.9 % of boys and 96.9 % of girls. Among children with a reduced daily intake of calcium and vitamin D, 42.9 % of children had a reduced level of total and / or ionized calcium, 48.2 % had a reduced level of vitamin D in the blood serum, and 53.6 % had a reduced calcium content in the hair. After 3 months of correction, we found that in the hair of children in the main group, who underwent dietary correction and were prescribed calcium and vitamin D, a significant increase in the average calcium content (up to 293.6 ± 80.6 mg/kg; p < 0.01) was observed, while in control group children who received only a modified diet, had only a tendency to increase the average amount of calcium in the hair (up to 185.14 ± 82.38 mg/kg; p > 0.05). Conclusions. For most primary school children, nutrition is unbalanced, which does not meet all the needs of a rapidly growing and intensively developing child's metabolism. A significant number of children have eating disorders: they do not eat regularly, do not eat enough food, eat food while watching TV, just before bed, do not have lunch at school, like fast food, 10% of students are on various diets. Almost a third of schoolchildren have a deficiency of daily intake of proteins, fats, carbohydrates and energy, and half of schoolchildren have a deficiency in the consumption of dietary fiber, polyunsaturated fatty acids and monounsaturated fatty acids. Most students have a daily deficiency of iodine, magnesium, selenium, iron and calcium, vitamin E, biotin, vitamin D, retinol, vitamin C, carotene, pantothenate. Among children with reduced daily intake of calcium and vitamin D in 42.9 % of children a reduced content of total and / or ionized calcium in the blood was found, and in 53.6 % of children in this group - in the hair. The use of a non-invasive method of studying the calcium content in the hair allows to determine the calcium deficiency in the child's body and control the process of its recovery. For children with insufficient daily intake of calcium and vitamin D, it is advisable to recommend a diet modification with increased consumption of milk, dairy products, yogurt and cheese, beans, spinach, broccoli, other leafy greens, wheat germ, nuts, sesame seeds, fish. To correct the existing calcium deficiency, it is advisable to use calcium supplements with vitamin D, combining this with a modification of the diet with an increase in food that contains the nutrients mentioned above. Keywords: schoolchildren, food deficiencies, calcium, vitamin D.
High prevalence of vitamin D insufficiency and its association with BMI-for-age among primary school children in Kuala Lumpur, Malaysia
