Major Finding: Overall, 55% of children with rheumatologic conditions had vitamin D deficiency or insufficiency, with no significant difference between children with autoimmune conditions (56%) and children with nonautoimmune conditions (52%).
Data Source: An observational study of 254 consecutive children seen in a pediatric rheumatology clinic.
Disclosures: Dr. Pelajo reported that she had no conflicts of interest related to the study.
VANCOUVER, B.C. — Vitamin D deficiency and insufficiency are highly prevalent in the pediatric rheumatology population, according to the findings of retrospective chart review.
Slightly more than half of patients who were seen in a pediatric rheumatology clinic at Tufts Medical Center in Boston during an 11-month period had levels of vitamin D that were in the deficient or insufficient range, with no significant difference in prevalence between children with autoimmune conditions and children with nonautoimmune conditions.
“The most important take-home message is to look for it, no matter what their baseline condition,” lead researcher Dr. Christina F. Pelajo recommended.
“And I would look even more carefully in children with the risk factors”—namely, overweight status, black race/ethnicity, older age, and nonsummer season of the visit, she added.
The investigators reviewed the medical records of consecutive children visiting the center's pediatric rheumatology clinic between November 2008 and September 2009, and assessed associations between mean levels of vitamin D (serum 25-hydroxyvitamin D) and various factors. Study results were based on 169 children with autoimmune conditions (predominantly juvenile idiopathic arthritis and juvenile systemic lupus erythematosus) and 85 children with nonautoimmune conditions (Lyme disease, patellofemoral syndrome, hypermobility, and others). Two-thirds were girls, and the average age was 12 years.
The mean level of vitamin D was 28.1 ng/mL in the group with autoimmune conditions and 29.7 ng/mL in the group with nonautoimmune conditions, a nonsignificant difference, reported Dr. Pelajo, who is a research fellow at the center. Overall, 55% of children had levels of vitamin D in the range for deficiency (less than 20 ng/mL) or insufficiency (20–29 ng/mL), with no significant difference between the two groups.
The prevalence of deficiency was 23% in the children with autoimmune conditions and 14% in the children without; the prevalence of insufficiency was 33% and 38%, respectively.
Vitamin D levels did differ by race/ethnicity: Mean values were highest among white children (30.7 ng/mL), lowest among black children (17.9 ng/mL), and intermediate among children who were Hispanic (21.3 ng/mL), Asian Indian (20.2 ng/mL), and Asian (21.1 ng/mL).
Levels were lower in overweight children, compared with their counterparts who had a normal body mass index (24.1 vs. 29.5 ng/mL, respectively), and they decreased with increasing age.
Finally, levels varied by season of visit, with the highest values seen in summer (36.0 ng/mL) and considerably lower ones seen in fall (27.7 ng/mL), winter (25.7 ng/mL), and spring (26.3 ng/mL).
Children who took supplements had higher vitamin D levels than did their peers who took no supplements. However, when the supplemented group was stratified by dose, the difference relative to the nonsupplemented group was significant only for children who took supplements containing more than 400 IU of vitamin D3.
“Taking 400 IU is the same as not taking anything because it's such a low dose,” commented Dr. Pelajo.