Major Study Finds Severe Vitamin D Deficiency Linked to 33% Higher Hospitalization Risk for Respiratory Infections

A major new study provides powerful evidence for the importance of Vitamin D in fighting respiratory illness. Research led by the University of Surrey, published in The American Journal of Clinical Nutrition, has found a strong link between severe Vitamin D deficiency and hospitalization rates for infections like bronchitis and pneumonia.
In the largest study of its kind, scientists analyzed NHS data from the UK Biobank. They discovered that individuals with severe Vitamin D deficiency (below 15 nmol/L) were 33% more likely to be admitted to the hospital for treatment than those with sufficient levels (at least 75 nmol/L).

Addressing a Leading Global Cause of Mortality

The research focused on middle-aged and older adults, a group at high risk for severe respiratory tract infections. Lower respiratory tract infections like pneumonia and bronchitis rank among the top 20 leading causes of death globally for people aged 50-74, and in the top 10 for those 75 and older.
Lead author Abi Bournot, a BBSRC Food Biosystems PhD Research Fellow at the University of Surrey, emphasized the critical role of the vitamin. “Vitamin D is vital to our physical wellbeing,” Bournot stated. “Not only does it keep our bones and muscles healthy, its antibacterial and antiviral properties are also thought to help reduce the risk of respiratory tract infections.”

A Call for Action on Supplementation

The study’s findings translate this theory into hard data, highlighting a widespread public health issue. “Despite its importance… many people are deficient and do not meet the government’s recommended intake of 10 micrograms of vitamin D per day,” Bournot explained.
The researchers concluded with a clear public health recommendation. Supplementation, particularly during winter months with limited sunlight, is an effective way to boost levels and reduce the risk of serious infections. This is deemed especially crucial for older adults at higher risk of death from such infections and for ethnic minority communities in the UK, who face a higher risk of Vitamin D deficiency.

Strengthening the Case for a Vital Nutrient

This landmark study adds significant weight to the argument for maintaining adequate Vitamin D levels. By quantifying the hospitalization risk associated with severe deficiency, it moves the conversation from theory to actionable evidence, urging both individuals and health policymakers to prioritize this essential nutrient for better respiratory health outcomes.