Trying to correct vitamin D deficiency in the ICU won't improve outcomes, researchers found.
In the VITdAL-ICU study, high-dose vitamin D didn't reduce length of hospital stay, hospital mortality, or 6-month mortality, , of the Medical University of Graz in Austria, and colleagues .
The findings were simultaneously presented at the meeting.
Among the most severely vitamin D deficient, supplementation did reduce hospital mortality -- but it didn't shorten hospital stay or decrease 6-month mortality.
Low levels of vitamin D in the ICU has been linked to worse outcomes, but it's been hard to tell if the association is causal, Amrein and colleagues wrote. So they conducted their randomized, double-blind, placebo-controlled, study in five ICUs in their hospital system, enrolling 492 critically ill adult white patients with vitamin D deficiency (20 ng/dL or less).
Patients got either placebo or a loading dose of 540,000 IU vitamin D, followed by monthly maintenance doses of 90,000 IU for 5 months.
Amrein and colleagues found that the primary outcome of length of hospital stay wasn't different between those on vitamin D and those on placebo (20.1 days versus 19.3 days).
Nor was there any difference in hospital mortality or 6-month mortality.
They noted, though, that these patients had significantly better hand grip strength and physical performance after 6 months, which may suggest a potential benefit in the recovery and rehabilitation phase.
In a prespecified subgroup analysis of 200 patients with severe vitamin D deficiency, length of hospital stay was not significantly different between those supplemented and those on placebo (20.1 days versus 19 days).
But hospital mortality was significantly lower with vitamin D (28.6% versus 46.1%). This suggests that vitamin D replacement may diminish adverse outcomes in the ICU, such as nosocomial infections, the researchers said.
Still, 6-month mortality wasn't different between groups.
Amrein and colleagues noted that despite the high dose of vitamin D, only half of patients in the study hit levels above 30 ng/mL. This was likely related to the fact that many systems in critically ill patients are compromised -- including gastrointestinal function and the hepatic cytochrome P450 system involved in vitamin D metabolism.
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