PTH and secondary hyperparathyroidism: Difference insubnormal level (Calcidiol < 30 nmol/L): 62% (42–82%)Low level (Calcidiol <20 nmolL): 51% (30–72%)(25(OH)D3<30 nmol/L): 77% (62–92%)Difference in rate of secondary hyperparathyroidism (PTH > 5.5 pmol/L): 43% (25–61%)Difference in vitamin D level:S–25(OH)D3 –36 nmol/L (median)Difference in PTH level: 1 pmol/L (median)