ISLAMABAD, Jan 21 (ABC): Severe vitamin D deficiency is linked to a significantly higher risk of hospitalisation due to respiratory tract infections such as bronchitis and pneumonia, according to a new study led by the University of Surrey.
The study found that people with severe vitamin D deficiency, defined as blood levels below 15 nmol/L, were 33 per cent more likely to be admitted to hospital for respiratory tract infections compared with those who had sufficient vitamin D levels of at least 75 nmol/L.
In the largest study of its kind, researchers analysed National Health Service data from the UK Biobank to examine the association between vitamin D status and hospitalisation rates linked to respiratory infections. The research was carried out by scientists from the University of Surrey in collaboration with the University of Reading and the University of Oxford.
Middle-aged and older adults are particularly vulnerable to respiratory tract infections. Lower respiratory tract infections, including pneumonia and bronchitis, are among the top 20 leading causes of death globally for people aged between 50 and 74 years, and rank among the top 10 causes for those aged 75 years and above.
Abi Bournot, a BBSRC Food Biosystems PhD Research Fellow and lead author of the study at the University of Surrey, said vitamin D plays a vital role in physical health. She said that beyond supporting bone and muscle health, vitamin D also has antibacterial and antiviral properties that may help reduce the risk of respiratory infections leading to hospitalisation.
She added that despite its importance, many people do not meet the UK government’s recommended daily intake of 10 micrograms of vitamin D. Bournot said supplementation, particularly during winter months when sunlight exposure is limited, is an effective way to improve vitamin D levels and lower the risk of severe respiratory infections. She noted that this is especially important for older people and ethnic minority communities in the UK, who are more likely to be vitamin D deficient.
The study examined data from 36,258 UK Biobank participants. Researchers found that those with severe vitamin D deficiency had a 33 per cent higher rate of hospitalisation for respiratory tract infections compared with individuals who had adequate vitamin D levels. The analysis also showed that for every 10 nmol/L increase in vitamin D levels, the rate of hospital admission for respiratory infections fell by four per cent.
Dr Andrea Darling, a BBSRC-funded postdoctoral researcher at the University of Surrey and senior author of the study, said respiratory tract infections remain a major global public health concern. She said such infections can cause serious illness and lead to hospitalisation, placing additional strain on already overstretched health services.
She added that the observed link between higher vitamin D levels and lower hospital admission rates warrants further research. According to Dr Darling, the findings highlight the potential role of vitamin D supplementation and vitamin D-fortified foods in reducing hospitalisations from respiratory infections and easing pressure on healthcare systems.
The study was published in the The American Journal of Clinical Nutrition.