PTH and Hypercalcemia: After excluding the patients with hypercalcemia or renal failure; a VD3 plateau of 46.2 nmol/L was found that stabilized the serum PTH levels.8 However, in a study on 1370 children age 1–6 years, mean reported levels for VD3 and PTH were 86 nmol/L & 2.67 pmol/L, respectively.