In a significant number of primary school students, the diet is unbalanced, it does not meet all the needs of the child's metabolism, which is growing rapidly and developing intensively. Among CP violations, the most common were: consumption of food immediately before going to bed (83.6%), frequent consumption of cookies (82.1%), sweets (71%), rolls (63.7%), skipping lunches at school (41%) , consumption of food while watching TV (33.6%), irregular eating (14.3%), insufficient daily amount of food (13.7%), consumption of fast food (8.4%).
Deficiency of daily consumption of fats was observed in 42.4%, proteins - in 31.4%, carbohydrates - in 30.2%, energy - in 27.3% of children in grades 1-4. In 48.8% of children of this age group, a decrease in the amount of dietary fiber was determined in the daily consumption, in 66.9% PUFA, in 48.3% - monounsaturated fatty acids, in 18.0% - unsaturated fatty acids. In 90.7% of schoolchildren of this age group, a daily deficiency of iodine consumption was determined, in 80.8% - magnesium, in 69.2% - selenium, in 64.0% - iron, in 62.2% - calcium, in 39 .0% - zinc. Insufficient daily intake of vitamin E was observed in 95.4% of schoolchildren, biotin in 92.5%, vitamin D in 91.9%, retinol in 75.1%, vitamin C in 70.9%, 40.5% in 40.5% % - folates, 69.9% - carotene, 54.6% - pantothenate, 39.6% - riboflavin, 36.6% - niacin. According to many indicators, a reliable difference in the daily consumption of nutrients among boys and girls was determined.
According to the analysis of the nutritional value of daily rations, it was determined that the average daily calcium intake was 750.00 mg (norm - 800 mg) per day [603.00; 949.00] in boys and 646.00 mg (norm – 800 mg) per day [502.50; 744.50] in girls. Insufficient daily calcium intake was determined in 50.7% of boys and 70.7% of girls. The average daily intake of vitamin D among schoolchildren was 2.59 μg (norm - 5 μg) [1.68; 4.08] in boys and 1.97 μg (norm - 5 μg) [1.19; 3.08] in girls. A decrease in vitamin D intake according to gender was determined in 84.9% of boys and 96.9% of girls.
A comparison of the dependence of the calcium level in the blood and the consumption of nutrients showed that most often a high level of calcium in the blood is observed in the presence of high values of the consumption indicators of vitamin D (R = 0.45, p < 0.01), vitamin B12 (R = 0, 42, p < 0.01) and vitamin B6 (R = 0.40, p < 0.01). Low blood calcium had a significant negative correlation with daily intake of zinc, thiamin, iron (R = -0.40, p < 0.01) and manganese (R = -0.35, p < 0.01). The indicator of calcium content in hair was correlated with indicators of calcium content in blood and daily calcium intake (R = 0.62, p < 0.01). The maximum positive correlation values were observed between the level of calcium in the blood and the frequency of consumption of dairy products (p < 0.01). Low vitamin D levels were correlated with insufficient intake of fruit, meat, fish and vegetables (p < 0.01).
Children with reduced daily intake of calcium and vitamin D may develop subclinical calcium deficiency.Thus, among 56 healthy children with a reduced level of daily calcium and vitamin D intake, a reduced level of total calcium in the blood was determined in 2 boys (3.6%) and 13 girls (23.2%) (p < 0.01), ionized calcium - in 1 boy (1.8%) and in 8 girls (14.3%) (p < 0.01), vitamin D - in 8 boys (14.3%) and in 19 (33.9%) ) girls (p = 0.02) of this group. Decreased calcium content in hair was determined in 8 (14.3%) boys and 22 (39.3%) girls (p < 0.01).
Correction of the existing deficiency of calcium and vitamin D should be carried out by modifying the diet with an increase in the consumption of milk (in the absence of signs of lactase deficiency), sour milk products, yogurts and cheese, beans and beans, spinach, broccoli, other leafy greens, wheat germ, nuts, sesame seeds, fish, dried fruits against the background of taking calcium supplements with vitamin D, for 3 months. The use of a non-invasive method of researching the content of calcium in the hair allows both to confirm the calcium deficiency in the child's body and to control the process of its recovery.
The use of the developed linear regression equation allows you to calculate the personalized dependence of the level of calcium in blood and hair, as well as the level of vitamin D in blood serum, on a number of available nutritional factors.
