New research has suggested that a daily vitamin D supplement may help ward off colds, flu and various respiratory infections.
In a recent Finnish study, 164 male military recruits were asked to take either 400 international units (IU) of vitamin D or placebo pills daily for six months during winter, at a time when our vitamin D stores tend to decline.
The results found that the men who took the vitamin D supplement missed two days of work due to a respiratory infection, whilst the placebo group missed three days. Participants in the vitamin D group were also more likely to have not missed a single day of duty.
Around 50% of the vitamin D participants remained ‘healthy’ throughout the study, compared to 36% of the participants in the placebo group.
Lead author of the study Dr Ilkka Laaksi from the University of Tampere in Finland said this provided some evidence for the benefits of vitamin D in fighting respiratory infections and “may plan an important role in the body’s immune defences”.
One downfall of the study was that around the same number of participants in the vitamin D group, as the placebo group, reported having cold-like symptoms at some stage during the study.
Other recent studies have also been inconclusive regarding the effectiveness of vitamin D in warding off colds and flu. Some, like the Finnish study, have shown that vitamin D intake does make it less likely to contract the flu whilst others found the opposite was true.
It is suggested that larger clinical trials are needed before vitamin D can be properly recommended as effective in warding off colds and flu.