PTH and hyperinsulinemic hypoglycemia, familial, 4: In relation to vitamin D status, elevated PTH (secondary hyperparathyroidism PTH ≥65 ng/L, that is, 6.89 pmol/L) was detected in 55.81%, 31.30% and 27.57% of adolescents with vitamin D severe deficiency, deficiency and insufficiency, respectively.