Evaluation of vitamin D3 levels and morphotic parameters of blood in prematurely born children at six years of age

All measurements were taken between March and May 2017 at the Institute of Physiotherapy and Centre of Medical Innovative Research being parts of University of Rzeszow, Poland. At first, we analyzed perinatal questionnaires at local hospitals and clinics and then selected children born of premature deliveries. The following criteria for including into the study group were adopted: guardians’ and children’s consent for participation, birth before gestational age of 32 weeks, lack of neurologic and orthopaedic disorders. Inclusion criteria for the controls were as follows: guardians’ and children’s consent for participation, lack of neurologic and orthopaedic disorders, age matching that of the study group, birth at gestational age after 36 and before 42 weeks. The children’s parents gave their written informed consent to their children’ participation in the study. All the measurements were performed on the same day, starting with anthropometric measurements. Body height was measured with Seca 213 mobile stadiometer, with an accuracy of 0.1 cm. Body mass was measured using electronic scale OMRON BF 500, with an accuracy of 0.1 kg. The measurements were performed in standard conditions; children in underwear and barefoot, were standing in upright position, without bending knees. In case of all children, a basic anthropometric measures were performed and BMI was calculated. Assessment of morphotic parameters was performed with the use of the CellDyn 1700 device (Abbott Laboratories. USA) and vitamin D3 levels in serum was performed with the use of the VIDAS® 25-OH Vitamin D Total (bioMerieux, France). The VIDAS® 25-OH Vitamin D Total assay is therefore considered suitable for assessment of vitamin D status in clinical routine. Blood tests were performed by a nurse with 10 years of professional experience in this field. Each participant was examined only once. The approximate duration of involvement per participant, approximately 10 minutes.