Background:

It is well recognized that vitamin D has a direct effect in bone and muscle and has been associated as well with some rheumatologic diseases. Reports in children are scarce. The aim of this study was to determine the concentration level of 25(OH)D in a group of patients with systemic lupus erythematosus (SLE) and juvenile idiopathic arthritis (JIA) and compare them with healthy controls.

Methods:

Vitamin D (25(OH)D) was measured with isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS), PTH with immunoradiometric assay (IRMA), calcium, phosphorus and alkaline phosphatase by colorimetric assay in 37 patients with SLE, 37 patients with JIA and 79 healthy controls.

Results:

Mean 25(OH)D concentration levels were as follows: SLE 18.9 ± 7.92 ng/ml, JIA 21.97 ± 5.55 ng/ml and 23.6 ± 3.07 ng/ml in healthy controls. There was a significant difference between SLE patients vs. healthy controls (p <0.05); 29.7% of SLE patients, 35.1% of JIA patients and 31.6% of healthy controls had deficient levels of vitamin D.

Conclusions:

One third of the total sample of children in this study had deficient levels of vitamin D. Patients with SLE presented a significant difference compared with healthy controls.