The Link Between Vitamin D and Respiratory Health
In light of the coronavirus epidemic and the increased focus on respiratory diseases, we thought it would be a good idea to delve into research that looks at the link between vitamin D and the respiratory immune system.
These are worrying times for people the world over. As public spaces, schools and places of work shut their doors and governments encourage people to self-isolate, many of us find ourselves in the unfamiliar situation of physical isolation.
This is a vital precaution in the coronavirus action plan set out by the UK government to slow the spread of the disease, and has been put in place to protect the vulnerable in our society. However, self-isolation brings with it a host of other medical issues, from depression to vitamin D deficiency. This is the third research roundup in our series of science articles about vitamin D, and in it I would like to explore the importance of vitamin D in maintaining a healthy respiratory system.
For the latest medical advice on COVID-19, please check the NHS website.
Vitamin D and Respiratory Health
This research on vitamin D and respiratory health from 2009 opened the discussion:
Vitamin D appears capable of inhibiting pulmonary inflammatory responses while enhancing innate defence mechanisms against respiratory pathogens…
It was early days for this insight. The author was suggesting that it was a field ripe for randomised control trials (RCT) but not reporting on them.
Two years later, this author writing about vitamin D effects on lung immunity and respiratory diseases bemoans the continuing lack of RCTs but now has a suggested mode of action for vitamin D’s protective effect on lungs.
The effects of vitamin D within the lungs include increased secretion of the antimicrobial peptide cathelicidin, decreased chemokine production, inhibition of dendritic cell activation and alteration of T cell activation. These cellular effects are important for host responses against infection and the development of allergic lung diseases like asthma. Epidemiological studies do suggest that vitamin D deficiency predisposes to viral respiratory tract infections…
By 2016 in a review of Vitamin D effects on common respiratory diseases there was a sufficient number of papers to justify a review:
All the reviewed articles state that vitamin D deficiency is very common among patients with respiratory diseases. The present data regarding vitamin D and asthma is still controversial, but data about COPD* and TB are more encouraging.
*COPD is chronic obstructive pulmonary disease, i.e. pneumonia.
In 2017 the definitive study, vitamin D supplementation to prevent acute respiratory tract infections, was published by the BMJ. It offered an extensive meta-analysis of 25 RCTs covering 11,321 participants:
Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.
In the body of the document it is more specific: for those with significant deficiency below 10ng/ml, restoration of vitamin D levels to a normal 50ng/ml “cuts the risk of respiratory infection in half”.
Should I Take Vitamin D Supplements?
If you are spending much of the time indoors during self-isolation and are covered up when you go outside – and frankly who isn’t at this time of the year? – you are inevitably flirting with a vitamin D deficiency at those levels, the more so the darker your skin. Therefore, put bluntly, your risk of pneumonia might increase.
Now is the time to consider measures to top up your vitamin D, whether by taking supplements or by spending time in natural sunlight if you have access to an outside space. One option is to try our active patches – they offer a comprehensive source of vitamin D, as well as providing long-lasting benefits for joints and muscles.
Take a look at our article on ways to combat Seasonal Affective Disorder for some more tips.