Vitamin D Levels Linked to Reduced Risk of Respiratory Infections
Adequate vitamin D levels may significantly protect against influenza and other respiratory infections, according to recent research. A study cited by The Telegraph found that adults with severe vitamin D deficiency had a 33% higher risk of hospitalization due to respiratory infections compared to those with sufficient levels.
The findings highlight the importance of vitamin D, often called the “sunshine vitamin” because the body produces it through sun exposure, for overall health. While known for its role in bone and muscle health, vitamin D also appears to have antiviral potential.
Researchers from the universities of Surrey, Oxford, and Reading analyzed data from approximately 36,000 British adults, correlating vitamin D levels with hospitalizations for respiratory conditions, including viral and bacterial infections like influenza, pneumonia, and bronchitis. Previous research has also indicated a link between vitamin D deficiency and more severe cases of COVID-19.
The study revealed that individuals with very low vitamin D levels – below 15 nanomoles per liter (nmol/l) in the blood – faced a 33% increased risk of hospitalization for respiratory infections compared to those with optimal levels, exceeding 75 nmol/l. Each 10 nmol/l increase in vitamin D levels was associated with a 4% reduction in hospitalization risk. This research could influence public health recommendations regarding vitamin D supplementation, particularly during winter months.
The National Health Service (NHS) in the United Kingdom currently recommends vitamin D supplementation for the entire population during the winter, when sunlight exposure is limited. This recommendation is based on the understanding that vitamin D is the only supplement advised for universal use during this time.
Scientists believe vitamin D may protect against respiratory infections by boosting levels of antimicrobial peptides – substances with antibiotic properties – in the lungs. Similar findings from Queen Mary University of London (QMUL) also support the protective effects of vitamin D supplementation against acute respiratory infections, as detailed in a meta-analysis of 25 clinical studies across 14 countries.
That global study, published in The British Medical Journal, indicated that the protective effect of vitamin D is greatest in individuals with low vitamin D levels and when the supplement is taken daily or weekly, rather than in infrequent, larger doses. Researchers suggest that fortifying foods with vitamin D could provide a stable, low-level intake, potentially eliminating widespread deficiency, as has been observed in some countries. More information on the benefits of Vitamin D can be found online.
The findings align with the observation that common colds are more prevalent during winter and spring, when vitamin D levels are typically at their lowest. Learn more about protecting yourself during cold and flu season.
