Effects of Early Vitamin D3 Supplementation on Clinical Outcomes for Critically Ill Patients

Recent studies have highlighted a prevalent vitamin D deficiency in critically ill patients, ranging from 26% to 82%. These patients experience longer ICU stays, higher medical expenses, and increased sepsis-related mortality. The investigators conducted a multicenter clinical trial in Taiwan focusing on vitamin D and critically ill patients. In the first phase, the epidemiological investigation found significantly lower serum calcidiol levels of approximately 20.9 ng/mL compared to the normal range of 30-60 ng/mL in ICU patients. The second phase, a randomized control study, preliminarily demonstrated that supplementing 576,000 IU of vitamin D3 in critically ill patients with serum calcidiol levels below 20 ng/mL significantly reduced the risk of multidrug resistant bacterial infections within 30 days. An Austrian trial also showed that adequate vitamin D supplementation lowered in-hospital mortality in severely deficient patients. The importance of vitamin D supplementation for critically ill patients with vitamin D deficiency is evident, as their clinical prognosis is closely related to achieving adequate serum calcidiol levels. However, there are no clear international guidelines for dosing vitamin D based on deficiency severity. Therefore, a new clinical trial is needed to evaluate the benefits of early vitamin D supplementation in maintaining sufficient levels for critically ill patients. The investigators will enroll 240 patients with low calcidiol levels and provide varying supplementation doses to maintain their serum calcidiol levels ≥ 30 ng/mL within 30 days of ICU admission. The serum levels of calcidiol and PTH will be measured on Day 0, Day 7, Day 14 and Day 30 before and after vitamin D supplementation. The results will serve as a valuable reference for intensivists when formulating appropriate vitamin D treatment strategy to maximize clinical benefits for critically ill patients.