Martin Schoenbeck: How Vitamin D can help our respiratory system

Health is pretty much on everyone’s minds right now and a lot of people are wondering “is there anything I can do to improve my immune system?” We know that COVID-19 is killing some people, while others only have the mildest symptoms, and we are fed a daily up-date of grim figures which gives a sense of urgency to take our own health seriously like probably never before. 

We are all washing our hands incessantly, keeping the recommended two metres distance and feel like running a mile when someone coughs. But a question I keep hearing and seeing on social media is this matter of “improving my immune system”. 

In short there is no “on or off switch” to our immune systems, and it is not something that taking a fist full of vitamins or drowning in kale smoothies will assist us with. The only proven way to reduce our chance of catching COVID-19 is the sensible government advice on social distancing and hand washing. Self-isolation is also now finally having an impact on those desperate numbers, and hopefully in the next week or two we will finally see that much lauded “flattening of the curve”.

The immune system cannot be boosted — indeed if it was to be, we would possibly send it in to overdrive and find that we become unwell. If it was to work like this we would find auto-immune diseases such as allergies, asthma, and coeliac disease become worse, or appear where previously there was none. Indeed, an over-active immune response is responsible for damaging healthy tissues and cells in sufferers of these auto-immune illnesses. 

However, there are numerous nutrients, vitamins and minerals which are required to support the normal functioning of a healthy immune system, and it is here that we can perhaps shine a light on to some of the statistics which have come out during this COVID-19 pandemic. Of particular interest is the role Vitamin D plays in maintaining a healthy immune system. Clues to the effects of deficiencies can be seen in data coming from the USA.

In Milwaukee County, for example, nearly three quarters of those who have died of the virus were black. But only about a quarter of the county’s population is black. The data is here. We can see that all the usual reasons are being blamed, lower socio-economic groups, higher percentage of co-morbidities like diabetes and hypertension, less adherence to social distancing, and the list goes on. But one fact that seems to have had little interest is that vitamin D deficiency in black Americans is significantly higher than for the white population.

Vitamin D is primarily made from a reaction of the sun on our skin, and it is known that darker skins produce far less than their white counterparts in the same levels of sunlight. Given that these darker skins are living in temperate climates with very little winter sunlight and being covered up to keep warm, it is of little surprise that they have these deficiencies. 

But we should all take note… While African Americans show this trend most starkly, the UK population also has high levels of Vitamin D deficiency including in the white population. One quarter (rising to one third in winter) of the UK population are Vitamin D deficient. The data is here.

Vitamin D is obtained in the diet from dairy foods (milk, butter, cheese), eggs, cod-liver oil, oily fish, and to a lesser extent mushrooms. However, without adding sunlight, even diets rich in these foods often do not provide high enough levels. If you are following a restrictive diet, then matters are significantly worse. 

Why is Vitamin D so important?

While there is no specific research yet into COVID-19 and vitamin D deficiency (because this is a new disease and such research takes many years) we can perhaps look at other investigations relating to Vitamin D and respiratory health. Historically is was well documented that tuberculosis sufferers fared well when placed in sunlight, and indeed in the last 1918 flu pandemic, it was noted that patients treated outside in open air field hospitals had lower mortality than those being treated indoors. 

I would strongly suggest that people get out into the sunshine (we’re allowed to exercise outside) and consider supplementing if they are not already doing so. Other vitamins and minerals that help maintain healthy immune function are Vitamin C; B-complex ; and Zinc. These can be obtained by eating plenty of fresh vegetables and fruits; meat, fish and dairy, and whole-grains. Try to reduce processed and refined foods as far as possible, as these are low in essential nutrients, but high in salt, saturated fats and sugars. 

Exercise outside

In addition to the dietary measures mentioned, it is well established that exercise has a role in enhancing the body’s immune response. Regular exercise resets the immune system and it is important not to remain sedentary while we face the current “lockdown”. But it is a question of balance – too much intense exercise can damage immune function, so keeping to a moderate amount and type – which suits you – is important. NHS guidelines are for 150 minutes of moderate to intense activity per week, and no more than 75 minutes of vigorous intensity exercise per week. However, this is an individual thing as some one who is relatively unfit will find even a brisk two-mile walk “high intensity”, so the key is to build up activity levels slowly. This is less likely to stress the immune system. 

There is an abundance of self-help advice on the internet for many types of exercise, but one in particular can help with reducing stress and it is well known that stress can adversely impact our immune systems. It goes without saying that we are all under extra stress as we adapt to this new way of living. 

Walking in nature can really benefit us in times of stress, and it can also help to improve mood. There is strong scientific evidence to show that regular walking in natural surroundings can reduce depression and anxiety.

We are allowed one hour of exercise per day outside – I really urge folks to use it! Residents here in Lincoln are blessed with many beautiful outside parks, commons and lakes and it is easy to observe the two metre rules while outside walking, cycling or jogging  – and you’ll get a healthy dose of Vitamin D even when the sun isn’t shining. Use this time well to make the best of your health – you might even develop new routines you continue when this is all over. 

If you are concerned about either yourself of a member of your household suffering with COVID-19 symptoms, then go to the NHS website for help and advice on what to do for assistance.


— Martin Schoenbeck BSc (Hons) M.N.I.M.H. is a consulting medical herbalist and nutritionist working in Lincoln.

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