PTH and secondary hyperparathyroidism: BsmI polymorphism (BB genotype) has been associated with slower progression of secondary hyperparathyroidism and normal levels of calcitriol in pre dialysis CKD patients, and lower levels of parathyroid hormone (PTH) in hemodialysis, and a greater reduction in PTH levels in response to a single bolus of calcitriol therapy compared to patients with bb genotype [8, 9].