High-Dose Vitamin D Not Shown to Benefit Critically Ill Patients

Study shows administration of high-dose vitamin D to intensive care unit patients did not significantly reduce length of hospital stay or hospital mortality.

Vitamin D is one of the most talked-about vitamins lately, with news stories linking deficiencies to poor bone health, the potential for cognitive deficits, high blood pressure, and more. Some studies suggest that patients who are critically ill and have low vitamin D levels may be at increased risk for mortality and morbidity. Researchers have not been able to establish causality or determine whether supplementation could improve patients’ clinical status. Hovever, a study published in JAMA on September 30, 2014, reports that administration of vitamin D₃ to patients in the intensive care unit did not provide health benefits.

This randomized double-blind, placebo-controlled, single-center trial study looked at ICU patients. It enrolled medical and surgical patients (N = 492) who had documented vitamin D deficiencies, defined as <20 ng/mL, between May 2010 and September 2012. Patients received vitamin D₃ (n = 249) or placebo (n = 243) orally or via nasogastric tube. The researchers employed a loading dose of 540,000 international units followed by monthly maintenance doses of 90,000 international units for 5 months. This approach—using a loading dose&mdash;was intended to restore adequate 25-hydroxyvitamin D levels quickly.

The final analysis included 475 patients (237 in the vitamin D₃ arm and 238 in the placebo arm).

Despite the loading dose approach, only half of patients treated with vitamin D₃ achieved serum 25-hydroxyvitamin D levels >30 ng/mL. The severity of their illnesses may have interfered with vitamin D absorption. Few adverse effects were reported, indicating that the regimen is safe.

Both arms had similar lengths of hospital stay. Hospital mortality and 6-month mortality were also similar. Patients treated with vitamin D had significantly better hand grip strength and physical performance scale scores after 6 months, an advantage the researchers suggest could be a benefit in recovery and rehabilitation.

The most positive results occurred in a subgroup of 200 patients who were classified as having severe vitamin D deficiency. In this subgroup, while length of stay was similar to other groups, patients treated with vitamin D₃ had significantly lower hospital mortality, with 28 deaths among 98 patients compared with 47 deaths among 102 placebo-treated patients. Six-month mortality was similar regardless of whether patients received active drug or placebo. The researchers suggest that vitamin D may reduce some iatrogenic complications (eg, nosocomial infection) in patients who are severely deficient, but this is purely hypothesis.