Prevalence and association of vitamin D deficiency and mortality in patients with severe sepsis

Abstract

Background: Vitamin D is a steroid prohormone that regulates body calcium and phosphate metabolism. Recent studies have shown an association between low vitamin D status and high mortality in patients admitted to intensive care units. To date, there are limited data available specifically about severely septic patients in medical units.

Objectives: To determine the prevalence of vitamin D deficiency in severely septic patients and its clinical outcomes, including mortality rate.

Methods: A prospective observational study was conducted to investigate the prevalence of vitamin D deficiency and its association with 30-day mortality in patients with severe sepsis. Patients admitted to medical wards at our hospital between November 2014 and March 2015 were included in the study. A 25-hydroxyvitamin D level <20 ng/mL was defined as vitamin D deficiency, and <12 ng/mL as severe deficiency. For an association analysis, the patients were grouped into deficient versus not deficient and severely deficient versus not severely deficient.

Results: One hundred and ten eligible patients were enrolled. A total of 83 patients (75%) had vitamin D deficiency and 42 (38%) had severe deficiency. Despite an insignificant higher 30-day hospital mortality rate in vitamin D deficient versus non-deficient groups (16% vs 4%, p=0.18), the differences were significant between the severely deficient versus non-severe groups (23% vs 4%, p=0.02). The odds ratio of the 30-day mortality rate was 4.83 (95% confidence interval [CI], 0.60-38.77, p=0.14) for vitamin D deficiency and 7.69 (95% CI, 2.00-29.55, p=0.003) for severe deficiency.

Conclusion: The prevalence of vitamin D deficiency was very high in three-quarters of patients with severe sepsis. A significant higher mortality rate was observed, particularly in patients with severe vitamin D deficiency.

Keywords: 25-hydroxyvitamin D; medical unit; mortality rate; severe sepsis; vitamin D deficiency.

Figure 1

Kaplan–Meier curve for overall survival in septic patients with severe vitamin D deficiency, 25(OH)D level <12 ng/mL. Abbreviation: 25(OH)D, 25-hydroxyvitamin D.