Critically ill and injured patients admitted in the intensive care unit have a range of diseases with various severities. Their conditions should be assessed and the patients should receive specialized nutrition therapy depending on their condition. Like general intensive care, nutrition therapy is upgraded every few years with revised information to provide more idealized nutrition support. The main guidelines in this review are from the Society of Critical Care Medicine (SCCM) and American Society for Parenteral and Enteral Nutrition (ASPEN). Their previous 2009 guidelines were revised and published in 2016. This review summarizes the 2016 SCCM/ASPEN guidelines focusing on the changes from the previous 2009 guidelines.

Vitamin D deficiency is a commonly observed global phenomenon in both the general population as well as hospitalized patients, especially critically ill patients. Many studies have demonstrated an association between vitamin D deficiency and risk of chronic diseases, including cardiovascular disease, diabetes, cancers, autoimmune diseases, and infectious diseases. Vitamin D deficiency is also associated with multiple adverse health outcomes, including increased morbidity and mortality in critically ill patients. The purpose of this review article is to present the current knowledge of clinical outcomes as well as the positive and adverse effects of vitamin D supplements on the relationship between vitamin D status and critical illness. In addition, future strategies for dealing with vitamin D deficiency are suggested.