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.
Meta-analysis
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.
Source: Nutrients
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