Background: The aim of our study is to determine the relation of vitamin D levels (25(OH)VD) with body-mass index (BMI), age and month of extraction in pediatric patients.
Materials and Methods: We present a retrospective review of medical records of patients under 18 years of age visited by the Children's Endocrinology Service (overweight and obesity) and ambulatory pediatrics (healthy and normal weight children) at our hospital between June 2016 and June 2018. We examined 176 medical records and made a correlation analysis in all parameters. We classified our patients according to their BMI and compared their 25(OH)VD levels (Chemiluminescent Immunoassay)with their BMI, age and month of extraction. The cut-off points of 25(OH)VD used are the ones suggested by Holick.
Results: The medical records of 176 patients (women:93/men:83) were reviewed, mean age: 10.2 years, 95%CI:9.5-10.9. Of the total of 25(OH)VD determinations obtained, we observed levels of sufficiency (≥30 ng/ml) in 33.5% patients, insufficiency in 43.2% (20-29 ng/ml) and deficiency in 23.3% (<20 ng/ml). We detected significant negative relationship between 25(OH)VD and BMI (r: -0.227, p: 0.003), and between 25(OH)VD and age (r: -0.273; p: 0.000); and significant positive relationship between 25(OH)VD and month of extraction (r: 0.2354, P=0.001), increasing levels during summer months (August, average: 49.8ng/ml, 95%CI:15-110) and decreasing during winter (January, average: 21.3ng/ml, IC95%: 16-26.7). There is also a progressive fall in values of 25(OH)VD since 10.5 years of age (mean: 24.1 ng/ml, 95% CI: 18.3-29.8).
Conclusions: These results suggest that there is an inverse association between BMI and 25(OH)VD levels. Vitamin D decreases significantly during winter and from the beginning of puberty, moment of great vulnerability due to the fact that the maximum peak of corporal growth takes place.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology