vitamin D and asthma

Could there be a link between vitamin D and asthma prevention?

Coughing, wheezing and struggling to breathe during everyday activities are the daily experience of many asthma sufferers. Asthma is a common long-term condition- around one in 11 people in the UK have it. Of these, less than 5% suffer from severe asthma. This means it’s difficult to breathe almost all the time, and asthma attacks can be life-threatening if not well managed.

Severe asthma needs additional specialist treatment, but promising new research has linked a reduced risk of severe asthma attacks with taking daily oral vitamin D supplements. The study found that a course of vitamin D tablets could halve the risk of severe asthma attacks needing emergency hospital treatment- from 6 in 100 down to 3 in 100.

Vitamin D is known as ‘the sunshine vitamin”- it’s produced in the skin when exposed to sunlight. Around 1 in 5 people have low levels of vitamin D due to not getting enough sunlight, especially during the winter, and may need to take supplements. Vitamin D can also be sourced from certain foods including oily fish like tuna, mackerel or salmon, and eggs.

What is asthma?

People with mild or moderate asthma can feel fine most of the time, but ‘attacks’ where they experience sudden difficulty breathing can be caused by certain triggers, which cause airways to become inflamed.

These triggers can be allergens, irritants, or other factors. Allergens are things that cause an allergic reaction, leading to inflammation of the airways and difficulty breathing. These can be substances like pet fur, mould spores, pollen, or dust mites. Irritants are substances that irritate the lungs, such as exhaust fumes or cigarette smoke.

Exposure to the cold, exercise and colds and flu might also trigger asthma symptoms, as all of these cause narrowing of the airways.

The research

The review was carried out by Professor Adrian Martineau and his team at Queen Mary University of London. They collected data from nine different trials, involving 658 adults and 435 children, most of whom had mild to moderate asthma. Some participants had severe asthma.

The review found that taking vitamin D supplement tablets while continuing to take regular asthma medication reduced the risk of severe asthma attacks, without harmful side effects.

However, vitamin D didn’t do anything to improve day-to-day asthma symptoms or lung function. The study also didn’t control for baseline vitamin D levels in the participants- which means the effects might only be seen in those who were vitamin-D deficient when the study began.

Exactly how vitamin D reduces the risk of severe attacks is unclear. It’s thought it may play a role in strengthening immune system response, preventing upper respiratory tract infections which can cause airway inflammation. It may also reduce airway inflammation directly.

For more information, you can read the study itself published in the Cochrane Review, or a news article summarising its findings.

Symptoms of asthma

If you or your children are experiencing any of the following symptoms, it’s a good idea to check up with your GP.

  • Coughing or difficulty breathing easily
  • A feeling of tightness in the chest
  • Wheezing sounds during breathing

It’s a good idea to keep a record of your symptoms, such as writing down when you feel breathless, and thinking about what triggers might have caused it (such as allergens or irritants). This will help your GP to work out what’s happening. You can also take the NHS Asthma Self Assessment to see if your symptoms resemble asthma. However, go to your local GP for a full assessment and diagnosis.

Get help

Asthma UK has a Helpline on 0300 222 5800 that operates between 9am and 5pm Mondays to Fridays. Their expert team of asthma nurses can answer questions about asthma medication, symptoms, and attacks.

This article on World Asthma Day covers self-care for asthma sufferers.

If you’re in East Berkshire and need asthma medication or care out of hours, EPCOOH is here to help. We are open 6.30pm to 8am, Monday to Friday, and all day Saturday and Sunday and bank holidays.