Vitamin D has never been more in the spotlight than in the last 12 months, when it became a highly recommended supplement to take to help in the battle against coronavirus. However, even before Covid 19 struck, this vitamin has always been vital for our overall health, so it is therefore concerning that 1 in 5 adults and 1 in 6 children in England have low levels of vitamin D, with an estimated 10 million people across England said to be deficient in vitamin D. Could you be one of them?

One of the biggest roles of vitamin D in the body is that it helps the absorption of calcium. Without vitamin D, calcium from food and supplements cannot be absorbed and thus one of the most well-known diseases associated with vitamin D deficiency is rickets (soft, thin bones) and osteoporosis. Over the last few years however, scientists have discovered that vitamin D actually plays a far greater role in our health than first realised and has shown to be vital in healthy immunity, respiratory function and cardiovascular health. Vitamin D deficiency has also been increasingly linked to some cancers, mental health problems and diabetes as well as autism.

It’s recent boost in popularity due to Covid 19 was mainly due to a large study in 2017, which showed that taking Vitamin D reduces the odds of developing a respiratory infection, and as Coronavirus specifically affects the respiratory system, anything that can be done to strengthen and support this area is vital. Studies have also shown that Vitamin D has a big role to play in the activity and healthy functioning of white blood cells, with low vitamin D levels shown to increase the risk of colds and flu, which have again been very much in the spotlight in recent months. Vitamin D also has a big part to play in helping fight respiratory tract infections too.  All of this perhaps helps demonstrate why this little vitamin is getting a lot of hype at present.

What’s important to know though is that only a small proportion of our Vitamin D requirements come from food and approximately 90% of our requirements come from sunlight, something which we severely lack here in the UK. British winters are particularly problematic due to reduced sunlight and the fact that between October and April time, the sunlight we do get is of the wrong wavelength to actually create vitamin D in the skin. This is why vitamin D deficiency increases during the winter months, especially in those already in the ‘at risk’ groups stated further below in the article. The recent cross-sectional National Diet and Nutrition Survey reveals that 8.4% of UK white 19–64 years old have vitamin D deficiency (< 25 nmol/L) in the summertime, which rises to 39.3% in the winter months. Results of another recent study show that in the right conditions white Caucasians in the UK need nine minutes of daily sunlight at lunchtime from March to September for Vitamin D levels to remain ≥25 nmol/L throughout the winter months. So this highlights the importance of stepping outside in your lunch break during the summer months and soaking up those rays as much as you can, or at least 9 minutes of it daily!

In 2016, Public Health England (PHE) published new guidelines on Vitamin D, which came as a direct result of the increased incidence of low Vitamin D levels in the English population. The guidelines now state that adults and children over the age of one should have 10 micrograms (mcg) of vitamin D EVERY day. This means that some people may want, or indeed need, to consider taking a daily supplement. The foods that you can obtain a little Vitamin D from include eggs, oily fish such as salmon and mackerel, fortified foods and some mushrooms, so always a good idea to have at least some of these in your  diet even though you cannot eat enough to provide you with all the vitamin D your body needs.

Although vitamin D deficiency can occur in anyone and across all age groups, there are some people within the population who are at an increased risk of deficiency. These include: people aged 65 and over along with children under the age of 5, pregnant and breastfeeding women, people who have minimal sun exposure, for example those people who are housebound, those who infrequently spend time outdoors and those people who cover up their skin with clothing. Another group of people at risk of deficiency include those people with darker skin such as those from Asian, African or African- Caribbean origin have more melanin in their skin compared to those with fairer skin. This increased melanin slows down vitamin D production.

So if you think you could be at risk of low vitamin D levels (and heed the warning that many people are), look at taking a supplement of it. You don’t even have to take a tablet anymore as it is available as an oral spray to apply directly into the mouth. There is of course nothing better than feeling the glow and warmth of sunlight on exposed skin, but as we are all now more aware of the dangers of skin cancer the use of sun cream has soared.   This of course is vital and necessary, but is not great if used excessively or for just small ten minute outings as it stops vitamin D production. A small amount of sun exposure without sun cream protection is OK, but make sure you cover up and use sun cream before you turn red or begin to burn.

If you needed any more of an excuse or reason to get out in nature on a sunny day then this is it. Go soak up those sun beams.



Meeting Vitamin D Requirements in White Caucasians at UK Latitudes: Providing a Choice, 2018. Nutrients

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data, 2017 British Medical Journal

Vitamin D and covid-19, 2021. British Medical Journal

Vitamin D and the Immune System, 2011. Journal Investigative Medicine

The Role of Vitamin D in Cancer Prevention and Treatment, 2010. Endocrinology and Metabolism Clinics of North America

National Institute for Health and Care Excellence, 2014.
Public Health England. Vitamin D: All you need to know, 2014 https:// problems

Scientific Advisory Committee on Nutrition
Natural Vitamin D Content in Animal Products, 2013.  Advances in Nutrition. An International review Journal.