PTH and hyperinsulinemic hypoglycemia, familial, 4: Serum median PTH levels were significantly different depending on vitamin D status (deficiency 42.0 ng/L, range 11.7-139.3; insufficiency 33.0 ng/L, range 10.9-95.4; sufficiency 26.8 ng/L, range 10.0-52.2, p < 0.0001).25-OH-D and PTH levels significantly differed depending on season of blood withdrawal, as showed in Figure 2.