[Assessment of bone mineralization and dietary intake of select nutritional components in school children from Łódź]

Development of bone mass, except genetic disposition, is modulated by environmental factors, especially diet. THE AIM of this study was to evaluate the skeleton mineralization and the influence of some nutritional components on bone mineralization in school children.

The study comprised 170 healthy children (92 girls and 78 boys) aged of 9,1-14,7 years, attending schools in Łódź. Mean dietary intake of calcium, phosphorus, potassium, natrium, magnesium, vitamin D and protein was assessed by a 3-day diet interview. Nutritional analysis was performed by computer program Dieta2. Bone mineralization was evaluated by ultrasound examination of the calcaneous with Achilles Solo plus apparatus. Speed of sound (SOS), broadband ultrasound attenuation (BUA) and automatically calculated Stiffness index were analysed. Reference values were accepted as +/- 1,00 standard deviation from mean values for sex and age (Z-score).

A lot of abnormalities in dietary intake of chosen nutritional compounds were found: significantly low vitamin D intake in all studied school kids (mean - 23% of reference daily intake, in children with vitamin D supplementation - 36.1%), calcium deficiency in 148 children (mean daily intake - 62.1% of reference uptake) and magnesium deficiency in 82 children. In all examined subjects high natrium consumption was found (mean 659.9%) and increased protein intake in 142 and phosphorus in 127 children were observed (152.9% and 135.5% of reference daily uptake, respectively). Decreased Z-score values for Stiffness index in 37 school kids, for SOS in 75, and for BUA in 15 were observed; the lowering of at least of one of the examined parameters was found in 79 children (46.5%). Increased Stiffness index was stated in 25 subjects, SOS in 8, and BUA in 54.

Results of this study indicate that vitamin D, calcium and magnesium deficiency and evaluated consumption of natrium, protein and phosphorus are very common in the diet of school children. These abnormalities may decrease skeletal mineralization in the developmental age, and also later in the life.