A report on two siblings with vitamin D resistant rickets treated with 1 alpha-hydroxy-vitamin D3 until completion of the growth]

The treatment of vitamin D resistant rickets still raises much controversy. This report describes out experiences on 1 alpha OHD3 treatment in two siblings from childhood till completion of the growth. The treatment began from age 3 and 8 in these two patients respectively. The daily doses were necessary to maintain the healing and increased during the growth period so that the doses per body weight were virtually constant at 1 microgram/kg/day. Under this regimen, the improvement of rickets was recognized in the radiogram, and the lower leg deformity corrected. In one case the bone biopsy confirmed the improvement of disturbed calcification. The final height was 152.5 cm (-0.8 SD) and 149 cm (-1.4 SD) respectively suggesting the effectiveness of 1 alpha OHD3 on the growth promotion. Around the closure of growth plate, the regimen induced hypercalcemia. Thereafter the doses were reduced to one fourth or one fifth of those in the growth period.