Vitamin D status is insufficient in the majority of children at diagnosis of nephrotic syndrome.

INTRODUCTION

Children with nephrotic syndrome (NS) are treated for at least 12 weeks with high doses of prednisolone, which may be harmful to the bones. Vitamin D deficiency is also harmful to the bones.

METHODS

This was a prospective study of consecutive children with first episode of NS at the time of their diagnosis before treatment with glucocorticoids. The following plasma levels were measured: 25-hydroxy-vitamin-D (25(OH)D), albumin, ionised calcium, phosphate, parathyroid hormone (PTH), alkaline phosphatase and creatinine. The glomerular filtration rate (GFR) was estimated from the Schwartz formula, and only patients with normal values were included.

RESULTS

A total of 14 children were examined, 13 (93%) had 25(OH)D deficiency including 12 (86%) with moderate or severe vitamin D deficiency. The plasma 25(OH)D was positively associated with plasma albumin (p = 0.031) and negatively with PTH (p = 0.003), phosphate (p = 0.016) and body mass index percentile (p = 0.022). PTH was negatively associated with albumin (p = 0.019) and the estimated GFR (p = 0.007), and positively associated with phosphate (p = 0.008), 24-h urine protein/m2 (p = 0.018) and systolic blood pressure percentiles (p = 0.048).

CONCLUSION

The vitamin D status was insufficient in 93% of the patients. We suggest that vitamin D status in children with NS be measured routinely at the time of diagnosis so that an individual treatment strategy for vitamin D deficiency can be given. Further studies are needed to evaluate the effect of such treatment.