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

A very limited number of intervention trials, most including less than 30 patients, have been published. The only phase III study, our VITdAL-ICU study recruited from 2010 to 2012 and (n=475) did not find a difference in the primary endpoint "length of hospital stay" between placebo and high-dose vitamin D3. However, there was a non-significant absolute risk reduction in all-cause hospital mortality in the total population. The difference was larger (17.5%) and significant in the predefined subgroup of patients with severe vitamin D deficiency at baseline, see Kaplan Meier curve below (n=200, 28.6 vs 46.1%, p=0.01, 0.56 (0.35-0.90) ), corresponding to a number needed to treat of 6. (51) As this was only a secondary endpoint in the predefined subgroup with severe vitamin D deficiency, this finding is hypothesis generating and requires further study, leading to this application.

In our study, we were unable to identify a mechanism by which this benefit was achieved. Interestingly, looking at the causes of death, the vitamin D group seemed to benefit in every category.

The VITDALIZE study is a pragmatic, multicenter, placebo-controlled double-blind randomized controlled phase III trial in adult critically ill patients which will be conducted in academic and non-academic centers. The sponsor is the Medical University of Graz, Austria.

Subjects will be randomised in a 1:1 ratio to receive either of the two treatments:

Vitamin D: oral/enteral pharmacological dose of cholecalciferol (vitamin D3)

• total dose 900,000
• loading dose of 540,0000 (dissolved in 37.5 ml of medium chain triglycerides - MCT) followed by 4000 IU daily (10 drops) for the entire active study period (90 days)

Placebo: identical regime - loading dose of 37.5 ml MCT followed by 10 drops daily

This study uses a group sequential design, with one interim analysis when 50% of the planned enrolled patients in each arm (N=600 per arm) have completed their day 28 assessment by the independent data safety monitoring board. The enrollment of patients will continue while the interim analyses is performed.

Inclusion criteria

• ≥18 years
• Anticipated ICU stay ≥ 48 hours
• Admission to ICU ≤ 72 hours before screening
• Severe vitamin D deficiency (≤12 ng/ml or undetectable)

Exclusion criteria

• Severe gastrointestinal dysfunction (> 400 ml residual volume)/unable to take study medication
• Do not resuscitate (DNR) order/imminent death
• hypercalcemia
• known recent nephrolithiasis, active tuberculosis or sarcoidosis
• pregnancy/lactation
• not deemed appropriate by study team/physician