The study, published in Nutrients, notes that previous evidence shows vitamin C supplementation may have a plethora of benefits which may cumulatively impact metabolism ad overall health.
Indeed, in previous clinical trials vitamin C has been found to lower blood pressure, decrease the incidence of atrial fibrillation, decrease broncho-constriction, decrease pain, decrease glucose levels in patients with type 2 diabetes, and shorten the duration of colds.
However, it is the potential benefit in for hospital stays that the authors focused on – noting that it is not uncommon for patients in hospital, and particularly those in intensive care units (ICU) to have very low vitamin C levels.
Dr Harri Hemilä from the University of Helsinki, Finland, and Dr Elizabeth Chalker from the University of Sydney, Australia, noted that a recent study of elderly Scottish patients hospitalised because of acute respiratory infections reported that 35% of patients had vitamin C plasma levels less than 11 μmol/L – which is the level at which scurvy becomes a risk.
“One study in a hospital in Paris reported that 44% of patients had vitamin C plasma levels less than 6 μmol/L,” noted the pair. “Another survey, of patients with advanced cancer in a hospice, found that 30% had vitamin C plasma levels less than 11 μmol/L.”
“Given this, it would seem reasonable to screen plasma vitamin C levels in hospital patients when appropriate and administer vitamin C to patients with particularly low levels,” they said.
Hemilä and Chalker added that although 0.1 grams per day of vitamin C can maintain a normal plasma level in healthy persons, much higher doses of up to 4 grams per day, are needed for critically ill patients to increase their plasma vitamin C levels to the range of normal healthy people.
Therefore, high vitamin C doses may be needed to compensate for the increased metabolism in critically ill patients.
The pair of researchers set out to analyse data from previously published clinical trials, in order to assess what benefit – if any – supplementation with vitamin C actually has on patients who are critically ill.
They identified 18 relevant controlled trials, and 12 of which were included in the meta-analysis on the length of stay.
Analysis of data the pooled data showed that on average, vitamin C administration shortened ICU stay by 7.8%.
Furthermore, they reported that in six trials, orally administered vitamin C with an average dose of 2 grams per day reduced the length of ICU stay on average by 8.6%.
“In three trials in which patients needed mechanical ventilation for over 24 hours, vitamin C shortened the duration of mechanical ventilation by 18.2%,” they added.
“Given the insignificant cost of vitamin C, even an 8% reduction in ICU stay is worth exploring,” they commented – adding that the effects of vitamin C on ICU patients should be investigated in more detail.
They said that further studies are needed to find optimal protocols for its administration – adding that a few studies of the common cold studies have also suggested there may be a linear dose response for vitamin C and duration for up to 6 and 8 grams per day.
“Evidently the dose response for doses higher than 2 grams per day should also be investigated for ICU patients,” they added.
Volume 11, Number 4, Page 708, Open Access, doi: 10.3390/nu11040708
“Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis”
Authors: Harri Hemilä, Elizabeth Chalker