Biochemical changes Normal or low serum calcium Serum phosphorus level less than 4mg/dl Serum aKP level elevated Low serum 25-hydroxycholecalciferolBiochemical changes ➢ Normal or low serum calcium ➢ Serum phosphorus level less than 4mg/dl ➢ Serum AKP level elevated ➢ Low serum 25-hydroxycholecalciferol