How deficient are vitamin D deficient critically ill patients?

Vitamin D deficiency is highly prevalent among critically ill patients and may be associated with adverse outcomes. Failure of conventional vitamin D supplementation in correcting deficiency has called for studies to evaluate the efficacy and safety of a high-dose regime in critically ill patients. High-dose vitamin D supplementation that corrects a deficient state effectively and safely allows for intervention studies to be undertaken to determine the impact of vitamin D on morbidity and mortality in critically ill patients.