Role of Vitamin D in Osteoarthritis: Molecular, Cellular, and Clinical Perspectives

Table 2

Common classifications of circulating vitamin D levels.

Classification	25(OH)D concentration
Sufficient	>20 ng/mL	>49.92 nmol/L
Insufficient	11–20 ng/mL	27.46–49.92 nmol/L
Deficient	<11 ng/mL	<27.46 nmol/L

25(OH)D₃ = 25-hydroxyvitamin D₃; to convert from ng/mL to nmol/L, multiply by 2.496.