Vitamin D: a new tool in critically ill patients?

Abstract

The detection of an ubiquitous vitamin D receptor in humans in the recent years has dramatically increased our knowledge regarding vitamin D effects. Besides its bone effects, pleiotropic effects of vitamin D have been reported in humans suggesting a key role for this hormone in metabolic control and immunity. To date, the impact of vitamin D insufficiency has been studied in the general population. However, recent studies have reported a high prevalence of vitamin D insufficiency in critically ill patients. Some data also suggest an association between vitamin D deficiency and hypocalcemia, bone demineralization, and mortality rate in the intensive care setting. Due to its role in immunity, we cannot rule out the possibility that vitamin D contributes enhance severe illness-related pro-inflammatory status resulting in increased morbidity and mortality. However, these hypotheses need to be assessed by large clinical studies in the intensive care setting. Furthermore, a possible beneficial effect of vitamin D supplementation, with or without associated calcium, remains to be demonstrated in well-designed randomized controlled trials.