Serum 25 (OH) D and 24,25 (OH)2 levels in childhood nephrosis under different therapeutic regimens of steroid administration.

The effect of prednisone therapy on serum levels of 25-hydroxyvitamin D [25(OH)D] and 24,25-dihydroxyvitamin D [24,25(OH)2D] was investigated in 16 children with nephrotic syndrome. These serum levels were significantly lower in patients before prednisone therapy than in age- and season-matched normal subjects. Patients receiving daily prednisone therapy had lower serum levels than those receiving alternate-day prednisone therapy at the time when the total amounts of the steroid administered attained 1,500 or 2,000 mg/m2 of body surface area. Daily doses of 40 mg/m2 of prednisone for 3 days caused a significant decrease in serum 25(OH)D levels. Withdrawal of the steroid for 4 consecutive days was followed by a significant recovery of the serum levels. These results suggest that alternate-day prednisone therapy rather than daily treatment should be used in clinical practice to help maintain normal vitamin D metabolism.