Intensive Care and Vitamin D Status

Vitamin D has receptors in a vast majority of cells, and thus a normal vitamin D state is preferable to ensure an adequate function and appropriate response of the different receptors to a multitude of changes, namely, in critical illness. Vitamin D has many sources and exists in two different forms. Vitamin D state is divided into sufficient, insufficient, and deficient, and the variety in levels depends on plenty of factors, including the role of vitamin D-binding protein and possible influences from testing assays. Other possibilities that may take place in case of acute illness are also taken into consideration and discussed here. This chapter deals with the general aspects of vitamin D role in acute illness and how a replete state may affect the outcomes. The prevalence of vitamin D deficiency in critical illness and the frequency of testing and correction in case of deficiency are all considered here. ▶Chapter 67, “Specific Considerations Relevant to Critical Illness” by Dr. Amrein et al., discusses specific considerations of critical illness where vitamin D may have a role