Serum 25-Hydroxyvitamin D and the risk of mortality in adult patients with Sepsis: a meta-analysis

Background Vitamin D deficiency has been related to the risk of sepsis. However, previous studies showed inconsistent results regarding the association between serum 25-hydroxyvitamin D (25 (OH) D) and mortality risk in septic patients. We aimed to evaluate the relationship between serum 25 (OH) D at admission and mortality risk in adult patients in a meta-analysis. Methods Follow-up studies that provided data of multivariate adjusted relative risk (RR) between serum 25 (OH) D and mortality risk in septic patients were retrieved via systematic search of PubMed and Embase databases. A random effect model was used to pool the results. Results Eight studies with 1736 patients were included. Results of overall meta-analysis showed that lower 25 (OH) D at admission was independently associated with increased risk or mortality (adjusted RR: 1.93, p < 0.001; I 2 = 63%) in patients with sepsis. Exploring subgroup association showed that patients with severe vitamin D deficiency (25 (OH) D < 10 ng/ml) was significantly associated with higher mortality risk (adjusted RR: 1.92, p < 0.001), but the associations were not significant for vitamin D insufficiency (25 (OH) D 20~30 ng/ml) or deficiency (25 (OH) D 10~20 ng/ml). Further analyses showed that the association between lower serum 25 (OH) D and higher mortality risk were consistent in studies applied different diagnostic criteria for sepsis (systemic inflammatory response syndrome, Sepsis-2.0, or Sepsis-3.0), short-term (within 1 month) and long-term studies (3~12 months), and in prospective and retrospective studies. Conclusions Severe vitamin D deficiency may be independently associated with increased mortality in adult patients with sepsis. Large-scale prospective studies are needed to validate our findings.