By Mark Lange, PhD
According to a study led by Queen Mary University of London, vitamin D has a protective effect against colds and flu. The analysis of raw data from 11,000 participants in 25 clinical trials conducted in 14 countries showed that vitamin D supplementation worked better in certain people. The protective effect of vitamin D supplementation was strongest in those who have the lowest vitamin D levels. Daily or weekly supplementation halved the risk of acute respiratory infection in people with the lowest baseline vitamin D levels. But supplementation also helped people with higher baseline vitamin D levels with a more modest 10% risk reduction. Vitamin D is thought to protect by boosting the levels of antimicrobial peptides, a natural antibiotic substance in the lungs.
Source: BMJ 2017; i6583 DOI: 10.1136/bmj.i6583