Relationship between low serum vitamin D status and urinary tract infection in children: a case–control study

A link between vitamin D deficiency and susceptibility to bacterial and viral
infections has recently been suggested.
Aim: To investigate a possible association between vitamin D deficiency and urinary tract
infection (UTI).
Methods: A case–control study was undertaken comprising 75 children aged 2–7 years with
UTI (cases) compared with 75 healthy controls in terms of serum 25 hydroxyvitamin D [25(OH)
D] levels. Serum 25(OH)D levels were measured using a chemiluminescence assay. For cases,
dimercaptosuccinic acid (DMSA) renal scan was used as the gold standard to distinguish
between acute lower UTI (cystitis) and acute pyelonephritis.
Results: Median (IQR) 25(OH)D levels were lower in the UTI group [14.5 ng/mL (9.4–18.8)] than in
the controls [27 ng/mL (22.4–39.0)] (p < 0.001). In addition, the prevalence of 25(OH)D levels
<20 ng/mL was higher in the children with UTI than in the controls (68% vs 18%) (p < 0.001). There
was a statistically significant difference between the cystitis and pyelonephritis groups in mean
(SD) serum 25(OH)D levels—18.76 (9.35) ng/mL vs 13.94 (6.97) ng/mL, p < 0.05, respectively.
Conclusion: Low serum vitamin D is associated with UTI and supports the hypothesis that
children with low vitamin D levels could be at greater risk of UTI.