Background
Cross-sectional studies of children with prevalent nephrotic syndrome (NS) have shown 25-vitamin D (25(OH)D) deficiency rates of 20–100 %. Information on 25(OH)D status in incident patients or following remission is limited. This study aimed to assess 25(OH)D status of incident idiopathic NS children at presentation and longitudinally with short-term observation.
Methods
Multicenter longitudinal study of children (2–18 years old) from 14 centers across the Midwest Pediatric Nephrology Consortium with incident idiopathic NS. 25(OH)D levels were assessed at diagnosis and 3 months later.
Results
Sixty-one children, median age 5 (3, 11) years, completed baseline visit and 51 completed second visit labs. All 61 (100 %) had 25(OH)D<20 ng/ml at diagnosis. Twenty-seven (53 %) had 25(OH)D<20 ng/ml at follow-up. Fourteen (28 %) children were steroid resistant. Univariate analysis showed that children prescribed vitamin D supplements were less likely to have 25(OH)D deficiency at follow-up (OR 0.2, 95 % CI 0.04, 0.6). Steroid response, age, and season did not predict 25(OH)D deficiency. Multivariable linear regression modeling showed higher 25(OH)D levels at follow-up by 13.2 ng/ml (SE 4.6, p<0.01) in children supplemented with vitamin D.
Conclusions
In this incident idiopathic NS cohort, all children at diagnosis had 25(OH)D deficiency and the majority continued to have a deficiency at 2–4 months. Supplemental vitamin D decreased the odds of 25(OH)D deficiency at follow-up, supporting a role for supplementation in incident NS.