The pleotropic effects of vitamin D on chronic diseases have received significant attention; however, its role in acute illness is less understood. The purpose of this review is to summarize the current evidence regarding the role of vitamin D in acute stress and critical illness.
25-Hydroxyvitamin D levels may affect risk of developing acute illnesses (e.g. respiratory infections), and low concentrations are associated with unfavorable outcomes during critical care. Inflammatory changes alone do not explain the observed deterioration in vitamin D status following acute stress. Hemodilution, interstitial extravasation, decreased synthesis of binding proteins, and renal wasting of 25-hydroxyvitamin D, all appear to play a more significant role in the regulation of vitamin D status during critical illness.
Single-point assessments of 25-hydroxyvitamin D following acute stress may provide an inaccurate assessment of vitamin D status. In such cases, measurement of binding proteins and free vitamin D metabolites may be essential to create a more realistic approximation of vitamin D status. Variations in patient responses to acute stress and critical illness may depend not only on the degree of systemic vitamin D insufficiency, but also on the individual tissue requirements.
aDepartment of Anesthesia, Critical Care and Pain Medicine
bDepartment of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Massachusetts, USA
Correspondence to Sadeq A. Quraishi, MD, MHA, Assistant Professor of Anaesthesia, Harvard Medical School, Assistant Anesthetist, Massachusetts General Hospital, Department of Anesthesia, Critical Care, and Pain Medicine, 55 Fruit Street, GRJ 402, Boston, MA 02114, USA. Tel: +1 617 643 5430; fax: +1 617 643 4502; e-mail: firstname.lastname@example.org