Alternative definitions of hyperparathyroidism used values based on intact PTH (iPTH) with in one study the iPTH-level > 4.1 pmol/L (66), and in another study iPTH > 8.5 pmol/L together with 25(OH) vitamin D < 50 nmol/L, and s-Calcium ≤1.35 nmol/L (68). The gene discussed is PTH; the disease is hyperparathyroidism.