Background: Vitamin D (VitD) deficiency and obesity are reaching epidemic proportions in North America, particularly in those with comorbid conditions such as diabetes or liver disease. The study objective was to determine the prevalence of suboptimal vitD status and interrelationships with anthropometric, cardiometabolic, liver, mental health, and lifestyle (sleep/screen time) parameters in an ambulatory population of children with obesity.
Methods: Children (2-18 years) attending a pediatric weight management clinic (n = 217) were retrospectively reviewed. Variables studied included anthropometric (weight, height, body mass index, waist circumference), vitD (serum 25-hydroxyvitamin D), cardiometabolic (systolic blood pressure, diastolic blood pressure, glucose, insulin, homeostasis model assessment for insulin resistance, triglyceride, high-density lipoprotein, low-density lipoprotein, total cholesterol), liver enzymes (alanine aminotransferase, gamma-glutamyl transferase), and mental health (number, diagnosis) parameters.
Results: Suboptimal vitD status (25-hydroxyvitamin D <75 nmol/L was present in 76% of children with obesity (12.0 ± 2.9 years). Blood pressure categorized as prehypertension, stage I hypertension, and stage II hypertension was present in 14%, 25%, and 7% of children, respectively. Mental health diagnoses including anxiety, attention-deficit hyperactivity disorder, mood disorders, and learning disabilities/developmental delays occurred in 18%, 17%, 10%, and 15%, of children, respectively. Waist circumferences >100 cm were associated with lower vitD levels (58 ± 18 vs 65 ± 17 nmol/L; P = 0.01). VitD status ≥50 nmol/L was associated with lower insulin (15.8 [11.7-23.1] mU/L vs 21.1 [14.3-34.2] mU/L; P < 0.01) and homeostasis model assessment for insulin resistance (3.5 [2.5-4.9] vs 4.8 [3.1-6.9]; P < 0.01) values and systolic blood pressure percentiles (73.0 ± 25.8 vs 80.6 ± 17.0; P = 0.04).
Conclusions: Children with obesity had a high prevalence of vitD deficiency, particularly those at risk for hypertension, reduced insulin sensitivity, and central obesity.