Skin pigmentation and sun exposure have a greater effect on circulating vitamin D levels than diabetes status in children, according to research in Pediatric Diabetes.
In multivariate analyses of Pediatric Diabetes Consortium data from 15 pediatric diabetes centers throughout the United States, researchers observed lowest vitamin D levels in black and Hispanic children, in fall and winter, and in children living in the North, but they also found that vitamin D deficiency and insufficiency were equally common in children with and without diabetes after adjusting for race and other factors.
Jamie R. Wood,
MD, of the Center for Endocrinology, Diabetes and Metabolism at Children’s Hospital Los Angeles, and colleagues analyzed data from 541 children aged at least 10 years enrolled in the Pediatric Diabetes Consortium (PDC), a group of treatment centers in the United States sharing best practices and outcomes data in a common database. Within the cohort, 215 children had type 1 diabetes (mean age, 14.5 years; 46% girls; 123 white; mean HbA1c, 8.5%); 326 had type 2 diabetes (mean age, 16.1 years; 63% girls; 191 Hispanic; mean HbA1c, 8.1%); vitamin D levels were measured between April 2012 and December 2013. Researchers collected socioeconomic data from medical records and parent interviews.
Researchers also analyzed vitamin D levels from the 2005-2006 National Health and Nutrition Examination Survey — calculated for the same age range — to compare vitamin D results with a national sample.
The overall mean vitamin D level for PDC participants was 24.8 ng/mL (95% CI, 23.7-25.9); NHANES participants in the same age range had a mean vitamin D level of 24 ng/mL (95% CI, 21.9-26.1). Within the PDC cohort, 36% were considered vitamin D deficient, and 34% had vitamin D insufficiency; in the NHANES data, 36% were vitamin D deficient, and 41% had vitamin D insufficiency.
Vitamin D deficiency varied by race in PDC data, with 65% of black children and 38% of Hispanic children considered vitamin D deficient vs. 14% of white children. In NHANES data, 83% of black children and 56% of Hispanic children were vitamin D deficient vs. 18% of white children. Results were similar for vitamin D insufficiency.
Vitamin D levels varied substantially among study sites and by season, according to researchers, with the highest levels observed in summer and the lowest levels in winter. HbA1c level and diabetes duration were not significantly associated with vitamin D levels.
“In multivariate analysis, only race/ethnicity (P < .001), study site (P < .001) and season (P < .001) were significantly associated with [25-hydroxyvitamin D] levels,” the researchers wrote. “Diabetes type was no longer significant.” – by Regina Schaffer
The researchers report no relevant financial disclosures.