Vitamin D adequacy: > 50 nmol/L at the end of winter (level may need to be 10–20 nmol/L higher at the end of summer, to allow for seasonal decrease).
• Mild vitamin D deficiency: 30–49 nmol/L
• Moderate vitamin deficiency: 12.5–29 nmol/L
• Severe vitamin D deficiency: < 12.5 nmol/L
(Ref: Med J Aust 2012; 196 (11): 686-687)
Note: > 250 nmol/L can be associated with toxicity and hypercalcemia.