Vitamin D Status and Markers of Cardiometabolic and Liver Disease Risk in Childhood Obesity

Abstract

Vitamin D insufficiency is highly prevalent in children (up to 40%), particularly in northern climates such as Alberta, due to reduced sunlight exposure and low intake. Although suboptimal vitamin D status and metabolic dysregulation are commonly observed in obesity, little is known about the interrelationships between vitamin D and body composition and the prevalence of co-morbid conditions (mental health disorders, cardiometabolic and liver dysfunction) in pediatric obesity. Two studies will be described. The first study is a retrospective chart review (n=217) of obese children attending the Pediatric Centre for Weight and Health (PCWH) at the Misericordia Hospital in Edmonton, Alberta. The second study focuses on two clinical populations of pediatric obesity: children with non-alcoholic fatty liver disease (NAFLD) and Prader-Willi Syndrome (PWS). Study findings indicate that rates of vitamin D insufficiency in obese children in Alberta (30-50%) are similar to levels in the general population, indicating that vitamin D status in children is independent of total body adiposity or the presence of co-morbid conditions such as mental health disorders. Children with PWS showed significantly lower muscle strength/muscle function compared to obese children with NAFLD or lean healthy children, and this was independent of overall vitamin D status. However, vitamin D insufficiency was related to an increased prevalence of hyperinsulinemia, insulin resistance and elevated systolic blood pressure in overweight and obese children, with/without the presence of other co-morbid conditions such as NAFLD or PWS. This has significant potential health policy implications in terms of the prevention and treatment of co-morbid conditions in childhood obesity.