The VITDALIZE Study: Effect of High-dose Vitamin D3 on 28-day Mortality in Adult Critically Ill Patients

This study tests whether giving a high dose of vitamin D3 to critically ill patients in the ICU who have severe vitamin D deficiency improves their chance of survival at 28 days. Vitamin D deficiency is very common in ICU patients and may worsen illness outcomes. This international randomized trial aims to find out if correcting this deficiency rapidly makes a meaningful difference. You may be eligible if: - You are 18 years of age or older - You are in the ICU and expected to stay for at least 48 hours - You were admitted to the ICU within the last 72 hours - Your vitamin D level is very low (12 ng/mL or less, or undetectable) You may NOT be eligible if: - You have severe gastrointestinal problems preventing you from taking oral medication - You have a do-not-resuscitate (DNR) order or are expected to die imminently - You have high blood calcium levels (hypercalcemia) - You have a recent history of kidney stones, active tuberculosis, or sarcoidosis - You are pregnant or breastfeeding - Your medical team does not think participation is appropriate Talk to your doctor to see if this trial is right for you.