Vitamin D reduces acute respiratory infections, new study shows

Scientists have discovered that high doses of vitamin D reduce respiratory infections, which could help to reduce one of the leading causes of serious illness, debilitation and death among older people residing in nursing homes and other long-term care facilities.

The study, which was carried out by the University of Colorado, is the first to examine the impact of vitamin D on respiratory infections in nursing home residents. It looked at 107 patients with an average age of 84 over a 12 month period. Of those, 55 received high doses of vitamin D or 100,000 units monthly (averaging 3,300-4,300 units daily), and 52 received lower doses averaging between 400-1,000 units daily. The results showed a 40 percent reduction in acute respiratory illness among those people who took higher doses of vitamin D.

In older people the immune system is often impaired but vitamin D appears to reinforce it, improving the ability to fight infections. This finding could prevent illnesses like pneumonia, influenza and bronchitis and it may also prevent infections and exacerbations of Chronic Obstructive Pulmonary Disease (COPD) like emphysema.

The study's lead author, Professor Adit Ginde, from the University of Colorado School of Medicine, said: “This is a potentially life-saving discovery. There is very little in a doctor's arsenal to battle acute respiratory infection (ARI), especially since most are viral infections where antibiotics don't work. But vitamin D seems able to potentially prevent these infections."

Professor Ginde cautioned that the study is not definitive proof that vitamin D can prevent ARI but it suggests that it can and at little risk to the patient. A larger trial is now required to confirm the findings.

The results of the study are published in the Journal of the American Geriatrics Society.


Has a sudden onset. Full medical glossary
Medication to treat infections caused by microbes (organisms that can't be seen with the naked eye), such as bacteria. Full medical glossary
Any of the main air pipes beyond the windpipe, or trachea, which have cartilage in their wall. Full medical glossary
Acute inflammation of the air passages within the lungs Full medical glossary
An abbreviation for chronic obstructive pulmonary disease. Full medical glossary
A viral infection affecting the respiratory system. Full medical glossary
The organs specialised to fight infection. Full medical glossary
Invasion by organisms that may be harmful, for example bacteria or parasites. Full medical glossary
A viral infection affecting the respiratory system. Full medical glossary
Inflammation of one or both lungs. Full medical glossary
Essential substances that cannot be produced by the body and so must be acquired from the diet. Full medical glossary