Vitamin D Insufficiency in Overweight and Obese Children and Adolescents

Abstract

Excessive body weight and obesity in childhood and adolescence are becoming more and more important unfavorable factors that entail extremely adverse consequences and require close attention of physicians of any specialty. Along with the high prevalence of obesity and metabolic syndrome in pediatric patients, children and adolescents in the majority of countries are diagnosed with vitamin D deficiency. Among the non-calcaemic effects of vitamin D, a significant role is played by its impact on the hormonal regulation of glucose metabolism and the synthesis of adipokines by fat tissue. The review presents literature data indicative of a close pathogenic relationship between vitamin D insufficiency and impaired tissue insulin sensitivity. It demonstrates the role of vitamin D insufficiency in immune reactions resulting in development of subclinical inflammation in fat tissue infiltrated with macrophages and lymphocytes. It also shows the role of adipokines, immune system cells and pro-inflammatory cytokines produced by them in the pathogenesis of obesity, as well as the function of vitamin D as an endocrine and paracrine regulator of the process of inflammation in adipose tissue. The relationships between the principal adipokines (leptin, adiponectin, resistin) are revealed in the presence of normal vitamin D content and in vitamin D deficiency. The carbohydrate and lipid metabolism parameters in overweight children and adolescents with vitamin D insufficiency are analyzed. A high prevalence of vitamin D insufficiency in overweight and obese children and adolescents (increasing along with the severity of obesity) is demonstrated. The review also presents the current recommendations for the correction of vitamin D insufficiency and underlines the need for higher cholecalciferol doses to achieve serum calcifediol targets in overweight and obese children and adolescents.

The Bones of Children With Obesity

“…Reduced levels of circulating 25-hydroxyvitamin D (25-OHD), which is pivotal for bone health and accrual, have been often reported in children with obesity as compared to normal weight peers. On purpose, we will not discuss this issue, which has been the focus of a number of recent excellent reviews (173)(174)(175). We will focus on the link between dietary fatty acids (FAs) and bone metabolism.…”

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

“…Interestingly, in diabetes, vitamin D supplementation promotes insulin secretion [ 80 , 141 , 158 , 159 , 160 , 161 , 162 , 163 , 164 ]. Indeed, 25(OH)D levels are typically lower in obese individuals who are more likely to develop diabetes mellitus and metabolic syndromes [ 165 , 166 , 167 , 168 ].…”

Vitamin D Deficiency is Associated With Higher Level of High Sensitivity C-reactive Protein (Hs-crp) in Patients Undergoing Elective Coronary Stenting

“…In addition, our results revealed that vitamin D de cient cases have signi cantly higher weight than patients with vitamin D levels above 20 ng/dl that is consistent with the result of studies reporting higher frequency of vitamin D de ciency in overweight and obese children and adolescents. (17) Several mechanisms have been described for the relation between vitamin D de ciency and increment in the risk for cardiovascular diseases (CVD). Low levels of vitamin D are believed to contribute to a rise in blood pressure.…”