Prevalence of hypovitaminosis D and its association with comorbidities of childhood obesity

PURPOSE: Our study sought to further delineate the prevalence of hypovitaminosis D and its relationship to comorbidities of childhood obesity.

METHODS: We conducted a retrospective chart review from 155 obese children aged 5 to 19 years who attended the Penn State Children’s Hospital Pediatric Multidisciplinary Weight Loss Program from November 2009 through November 2010. We determined the incidence of hypovitaminosis D and examined its association with comorbidities including elevated blood pressure, diabetes, acanthosis nigricans, depression, hyperlipidemia, hyperinsulinemia, and abnormal liver function test results, as well as age, sex, and geographic location.

RESULTS: Under the latest Institute of Medicine definitions, vitamin D deficiency (< 20 ng/mL) and insufficiency (20-29 ng/mL) was present in 40% and 38% of children, respectively. The prevalence of vitamin D deficiency was 27.8% in children aged 5 to 9 years, 35.4% in children aged 10 to 14 years, and 50.9% of children aged 15 years or older. Older age, African-American race, winter/spring season, higher insulin level, total number of comorbidities, and polycystic ovary syndrome (in girls) were significantly associated with vitamin D deficiency. African-American race, winter/spring season, hyperinsulinemia, elevated systolic blood pressure, urban location, and total numbers of comorbidities were significantly associated with hypovitaminosis D (< 30 ng/mL).

CONCLUSIONS: Hypovitaminosis D is associated with several medical comorbidities in obese children. Given the large percentage of children, even in our youngest age group, who are vitamin D deficient, obese children should be considered for routine vitamin D screening.