Vitamin D in acute stress and critical illness

Abstract

Purpose of review 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. Recent findings 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. Summary 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.

Vitamin D status after a high dose of cholecalciferol in healthy and burn subjects

“…Malabsorption of cholecalciferol may be another cause of supplementation failure: this problem arises in 13% of the general population [26] and may be worsen in burn patients due to gut edema or digestive hypoperfusion. Moreover, peripheral tissue requirements are suspected to be increase during critical stress, leading to a higher turnover [12]. Finally, a reduced 25-hydroxylation in case of absolute or relative hepatic failure may be considered in major burns but, to the best of our knowledge, has not been demonstrated yet.…”

“…For those later effects, such as muscle effects, cut-off values are not known precisely. Moreover, during acute illness, diagnosis of vitamin D deficiency is thought to be hazardous due to fluid shifts, fluctuations of binding proteins (mainly albumin, ALB, and vitamin D binding protein, DBP) or assays' limitations [12].…”

Effect of Cholecalciferol Supplementation on Vitamin D Status and Cathelicidin Levels in Sepsis

“…Cholecalciferol is converted to 25OHD in the liver and then to 1,25OH2D by the kidneys and by cells of the immune system (amongst others) for paracrine use [37]. Circulating 25OHD levels are, however, approximately 500–1000 times higher than 1,25OH2D levels, and both 25OHD and 1,25OH2D are predominantly protein-bound in circulation [38].…”

Serum Vitamin D Level in Children with and without Type 1 Diabetes Mellitus

“…However, in these studies, controls were healthy subjects, while in our study controls were children admitted to hospital or seen in emergency for other reasons and thus expected to have lower serum 25 OHD than healthy children supporting the role of vitamin D in defense mechanism [13]. In fact, low vitamin D level has been reported in both acute and chronic diseases [14,15]. It was implicated in cardiovascular diseases [16], kidney disease [17], asthma [18], multiple sclerosis [19], rheumatoid arthritis [20], several malignancies [21] and immune disorders [22].…”