Objectives: To determine the prevalence of 25-hydroxyvitamin D (25[OH]D) deficiency and associations between 25(OH)D deficiency and cardiovascular risk factors in children and adolescents. Methods: With a nationally representative sample of children aged 1 to 21 years in the National Health and Nutrition Examination Survey 2001-2004 (n = 6275), we measured serum 25(OH)D deficiency and insufficiency (25[OH]D <15 ng/mL and 15-29 ng/mL, respectively) and cardiovascular risk factors.

Results: Overall, 9% of the pediatric population, representing 7.6 million US children and adolescents, were 25(OH)D deficient and 61%, representing 50.8 million US children and adolescents, were 25(OH)D insufficient. Only 4% had taken 400 IU of vitamin D per day for the past 30 days. After multivariable adjustment, those who were older (odds ratio [OR]: 1.16 [95% confidence interval (CI): 1.12 to 1.20] per year of age), girls (OR: 1.9 [1.6 to 2.4]), non-Hispanic black (OR: 21.9 [13.4 to 35.7]) or Mexican-American (OR: 3.5 [1.9 to 6.4]) compared with non-Hispanic white, obese (OR: 1.9 [1.5 to 2.5]), and those who drank milk less than once a week (OR: 2.9 [2.1 to 3.9]) or used >4 hours of television, video, or computers per day (OR: 1.6 [1.1 to 2.3]) were more likely to be 25(OH)D deficient. Those who used vitamin D supplementation were less likely (OR: 0.4 [0.2 to 0.8]) to be 25(OH)D deficient. Also, after multivariable adjustment, 25(OH)D deficiency was associated with elevated parathyroid hormone levels (OR: 3.6; [1.8 to 7.1]), higher systolic blood pressure (OR: 2.24 mmHg [0.98 to 3.50 mmHg]), and lower serum calcium (OR: -0.10 mg/dL [-0.15 to -0.04 mg/dL]) and high-density lipoprotein cholesterol (OR: -3.03 mg/dL [-5.02 to -1.04]) levels compared with those with 25(OH)D levels >/=30 ng/mL.

Conclusions: 25(OH)D deficiency is common in the general US pediatric population and is associated with adverse cardiovascular risks.