['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.', '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.', '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).'] Is vitamin D status insufficient in the majority of children at diagnosis of nephrotic syndrome?