Analysis of subjects with elevated PTH stratified according to 25OHD concentrations is presented in Table 3, while evolution of individual concentrations of PTH, 25OHD and calcium is presented in Table 4, in keeping with Institute of Medicine guidelines (17) 25OHD sufficiency was defined as concentrations above 20 ng/ml (50 nmol/L), with 25OHD deficiency being only present for concentrations below 12 ng/ml (30 nmol/L), while 25OHD insufficiency was defined for concentrations 12-20 ng/ml (30-50 nmol/L). The gene discussed is PTH; the disease is hyperinsulinemic hypoglycemia, familial, 4.