Prevalence of hypovitaminosis D and associated factors in obese Spanish children

Abstract

Background/Objectives:Vitamin D deficiency may contribute to endocrine health and disease (diabetes, autoimmune thyroid diseases, polycystic ovarian syndrome, etc.). The aim of this study was to determine the prevalence and specific factors for hypovitaminosis D among children stratified by body mass index (BMI) in Northern Spain.Subjects/Methods:A cross-sectional clinical (sex, age, season of study visit, place of residence and BMI) and blood testing (calcium, phosphorous, calcidiol and parathyroid hormone (PTH)) were accomplished in 546 Caucasian individuals (aged 3.2–15.8 years). The BMI (Z-score) allowed establishing four groups: normal, overweight, obesity and severe obesity. The criteria of the US Endocrine Society were used for the definition of hypovitaminosis D.Results:Calcidiol levels were significantly higher in normal and overweight groups (P=0.001), whereas PTH levels were significantly higher in obesity and severe obesity groups (P=0.001). Hypovitaminosis D prevalence was significantly higher in severe obesity (81.1%) and obesity (68.2%) groups, whereas was lowest in overweight (55%) and normal (58.1%) groups (P=0.001). There was a negative correlation between calcidiol and PTH levels (P<0.01). Female (90.9%), adolescent group (88,2%), winter (100%) and autumn (82.4%) time and urban residence (94.1%) imply a higher prevalence of hypovitaminosis D in subjects with severe obesity (P<0.001). Female, puberal age, autumn, winter and spring time, urban residence and severe obesity were found to be independent predictors for hypovitaminosis D.Conclusions:Severe obesity could be considered as an associated factor for vitamin D deficiency, and, owing to its high prevalence, the implementation of systematic screening and hypovitaminosis treatment programs would be particularly useful.

Hypovitaminosis D and Cardiometabolic Risk Factors in Adolescents with Severe Obesity

“…On the other hand, obesity is a known risk factor for Vitamin D deficiency. In fact, circulating concentration of 25(OH)D is inversely associated with the severity of obesity [6][7][8]. Data on the relationship between hypovitaminosis D and the different components of metabolic syndrome, both in adults [9][10][11] and children with obesity [12][13][14][15][16] are, at present, inconclusive.…”

Peculiarities of the prevalence and risk factors for vitamin D deficiency in overweight and obese adolescents in Ukraine

“…The mean serum calcidiol content in blood serum of adolescents with obesity was 1.43 times lower than that of children with normal body weight. The data obtained during the study showed a similar trend of change in the status of vitamin D in children of different ages during epidemiological studies in Ukraine, but were lower compared with the data of the studies in the USA, Spain, and Italy 5,9 . Researchers explain the low levels of 25 (OH) D in blood serum by depositing calcidiol in the adipose tissue, reducing bioavailability, and reducing its synthesis under the influence of ultraviolet rays 14 .…”

“…Anthropometric examinations -body weight (within the accuracy of 0.1 kg), height (within the accuracy of 0.1 cm) -were carried out, with the use of generally accepted methods with the help of floor weight, height meter and flexible centimeter tape. BMIs were evaluated according to standard percentile tables 5,14 . Thus, children with BMI from 15 to 85 percentiles were assigned to the normal body mass, the excess body mass corresponded to 85-95 percentiles and over 95 percentiles -to the obesity.…”

“…"The authors declare no conflict of interest regarding this article" "The authors declare that all the procedures and experiments of this study respect the ethical standards in the Helsinki Declaration of 1975, as revised in 2008 (5), as well as the national law. Informed consent was obtained from all the patients included in the study" "This study was approved by the I. Horbachevsky Ternopil State Medical University Research Committee"…”

“…The presence of interconnections between calcidiol level and lipid and carbohydrate metabolism in children 5,6 has been established. Moreover, special attention is paid by the researchers to the assessment of cardiometabolic risk factors and their combinations with the concentration of calcium in the blood and levels of parathyroid hormone, under the conditions of vitamin D deficiency 7,8 .…”