Table 2.

Salient features of different types of rickets

Type	Calcium	Phosphorus	Alkaline phosphatase	PTH	25 (OH)D	1,25 (OH)2 D
Calcipenic rickets
Vitamin D deficiency	↓ or N	↓ or N	↑ or ↑↑	↑	↓	Variable
Vitamin D–dependent rickets type I	↓	↓ or N	↑↑	↑	N	↓
Vitamin D–dependent rickets type II	↓	↓ or N	↑↑	↑	N	N or ↓
Phosphenic rickets
Nutritional phosphate deficiency	↑ or N	↓	↑ or ↑↑	↓ or N	N	↑
X-linked hypophosphatemic rickets	N	↓	↑	N or slightly ↑	N	N or ↓
Autosomal dominant hypophosphatemic rickets	N	↓	↑	N	N	↓
Autosomal recessive hypophosphatemic rickets	N	↓	↑	N	N	↓
Hereditary hypophosphatemic rickets with hypercalciuria	N	↓	↑	N or ↓	N	↑

25 (OH)D, 25-hydroxy vitamin D; 1,25 (OH)2 D, 1,25 dihydroxy vitamin D; N, normal levels; PTH, parathyroid hormone; ↑, increased levels; ↓, decreased levels.