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.

Background: The aim of this study is to describe the effects of a prolonged dietary-behavioral-physical activity intervention (24 months) on body composition in a group of adolescents with obesity. Methods: Longitudinal study in 196 individuals with obesity (86 boys and 110 girls) aged 10.1-14.9 years that completed a prolonged combined intervention (24 months). Values for weight, height, skinfold thickness, waist circumference, BMI, body fat, fat mass index (FMI) and fat-free mass index (FFMI) were registered or calculated. A good response to treatment was reported when a BMI z-score reduction of greater than or equal to 0.5 units of the initial value occurred after 24 month of follow up. Results: A good response after 24 months of follow-up reached 58.2% (n = 114). In boys with obesity and BMI status improvement, weight z-score, BMI z-score, body fat, and FMI significantly decreased (p < 0.05). In girls with obesity and BMI status improvement, weight z-score, BMI z-score, waist circumference, waist z-score, body fat and FMI significantly decreased (p < 0.05). In both sexes the height and FFMI increased significantly (p < 0.05). The multiple logistic regression analysis showed that girls and younger age were associated with BMI status improvement; concurrently, the place of residence (urban or rural) and degree of obesity were not associated with BMI status improvement. Conclusion: The application of long-term combined strategies in the treatment of childhood obesity seems to be effective. As BMI decreases, a reduction in fat mass is also detected, with evident sexual dimorphism, in the absence of changes in fat-free mass and, consequently, in longitudinal growing.

Background/Objectives. Obesity is associated with cardiometabolic risk factors and with Vitamin D deficiency. The aim of this study was to examine the relationship between 25(OH)D concentrations and cardiometabolic risk factors in adolescents with severe obesity. Subjects/Methods. A cross-sectional clinical assessment (body mass index, fat mass index, fat-free mass index, waist-to-height ratio, and blood pressure) and metabolic study (triglycerides, total cholesterol, HDL-C, LDL-C, glucose, insulin, HOMA-IR, leptin, calcium, phosphorous, calcidiol, and PTH) were carried out in 236 adolescents diagnosed with severe obesity (BMI z-score > 3.0, 99th percentile), aged 10.2-15.8 years. The criteria of the US Endocrine Society were used for the definition of Vitamin D status. Results. Subjects with Vitamin D deficiency had significantly elevated values (p < 0.05) for BMI z-score, waist circumference, waist z-score, body fat percentage, fat mass index, systolic and diastolic blood pressure, total cholesterol, triglycerides, LDL-C, insulin, HOMA-IR, leptin, and PTH than subjects with normal Vitamin D status. There was a significant negative correlation (p < 0.05) of serum 25(OH)D levels with body fat percentage, FMI, systolic BP, total cholesterol, triglyceride, LDL-C, glucose, insulin, HOMA-IR, leptin, and PTH. Conclusions. Low Vitamin D levels in adolescents with severe obesity were significantly associated with some cardiometabolic risk factors, including body mass index, waist circumference, fat mass index, high blood pressure, impaired lipid profile, and insulin resistance.

Background Obesity is associated with vitamin D deficiency. The aim of this work is to analyze the changes in vitamin D status and PTH levels in a group of children with obesity receiving combined intervention program in order to get BMI status reduction. Methods Longitudinal study in 119 children with obesity, aged 9.1–13.9 years, included in a 1-year combined dietary-behavioral-physical activity intervention. Anthropometric measurements (weight, height, BMI and fat mass index) were registered every 3 months and blood testing (calcium, phosphorous, 25(OH)D and PTH) were collected at the beginning and after 12 months of follow-up. A control group was recruited (300 healthy children, aged 8.1–13.9 years). The criteria of the US Endocrine Society were used for the definition of hypovitaminosis D. Results Vitamin D deficiency was significantly higher in obesity group (31.1 vs. 14%). There was negative correlation between 25(OH)D and fat mass index ( r = −0.361, p = 0.001). Patients with BMI reduction throughout combined intervention were 52 (43.7%). There was a significant increase in the prevalence of hypovitaminosis D in patients without BMI reduction at the end of follow-up, but in those patients with BMI reduction there was no changes of vitamin D status. Conclusions Obesity increases the prevalence of suboptimal vitamin D status, and a BMI status reduction in children with obesity may be required to at least stabilize vitamin D status.