Vitamin D and coronavirus: are you getting enough natural sunlight?

When the skin is exposed to natural sunlight, it triggers the body to produce vitamin D.

The sunshine vitamin, along with others and important minerals, can help your body stay fit to help fend off illness and infections - especially important during a pandemic.

According to reports from the BBC in the UK, Public Health England is recommending that some people should consider taking vitamin D supplements throughout the spring and summer as coronavirus lockdown continues. 

Normally, most of us get enough vitamin D by going outside and exposing our skin to sunshine, but lockdown stipulations in many countries across the world are restricting opportunities to be outside for many.

Vitamin D helps to regulate the amount of calcium and phosphate in the body. These nutrients are needed to keep bones, teeth and muscles healthy.

People who do not have access to private outdoor space such as a garden, balcony or patio are faced with increased difficulty to access natural sunlight, as recommendations to avoid leaving home except for essential journeys (food shopping to go to the pharmacy - for example) are maintained, as a result of the coronavirus pandemic.

So the question is, can we obtain vitamin D by means other than sunlight? 

Vitamin D is found in a small number of foods.

According to the NHS (UK National Health Service) website, sources include:

• oily fish – such as salmon, sardines, herring and mackerel
• red meat
• liver
• egg yolks
• fortified foods – such as most fat spreads and some breakfast cereals

"Vitamin D has generated increasing interest in recent years, not only because of its main function in maintaining calcium metabolism, but also because of its extra skeletal effects - including protecting bone mineral density

“Although historically speaking vitamin D has been considered a “vitamin”, it is actually a hormone produced by the kidneys that controls blood calcium concentration and impacts the immune system. The main biochemical forms are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol)", says Dr. Elena Cuesta Narvaez, rheumatologist at the Vithas Virgen del Mar hospital in Almeria and member of Top Doctors. 

Vitamin D is a vital key nutrient required to develop and maintain bone health, the expert stresses. 

A chronic lack of vitamin D, known as a deficiency can have a lasting impact on bone health.

Vitamin D deficiency can lead to health problems, such as rickets in children, osteomalacia (softening of the bones in adults), osteoporosis and increased risk of fractures. 

Narvaez also points out that a vitamin D deficiency has also been linked to conditions such as asthma, some forms of cancer, heart disease, diabetes, inflammatory and autoimmune diseases (including type 1 diabetes, multiple sclerosis, crohn's disease, rheumatoid arthritis, systemic lupus erythematosus), respiratory infections and liver disease.

Narvaez explains that approximately 10-15 minutes of exposure to (on the arms and face with no sunscreen) provides enough radiation for the body to produce 10,000- 20,000 IU (international units) of vitamin D. Variables such as skin type, season, time of day (between 11am-3pm is considered optimal) and the use of sunscreen will impact the amount of vitamin D that the body can produce. 

Should everyone start taking a vitamin D supplement?

Some health experts suggest that taking a vitamin D supplement could be advisable, under certain circumstances.

"At this present moment of confinement, without infinite supplies of vitamin D supplements, suggesting everyone takes a vitamin D supplement is not a necessary scenario,” says Dr Narvaez.  

“Exceptional circumstances whereby patients require vitamin D supplementation due to illness, specific conditions or for bone fractures they would need to continue supplementation. Though certainly for the population in Spain, nationwide intake of vitamin D supplements is not considered necessary at this  point - as if predictions are accurate, access to public outside spaces could be available by the summer.”

Sara Stanner from the British Nutrition Foundation said: "Unfortunately, as the effects of coronavirus continue, many of us are limited in the time we can spend outdoors. Correctly abiding by government rules and staying at home is immensely important and, while many of us have limited access to sunlight, this means we need to take a little extra care to keep our vitamin D levels healthy."

According to the rheumatologist, there is currently some controversy surrounding how much vitamin D is optimal for the body. Below this, a supplement would be recommended. 

Public Health England recommends taking a vitamin D supplement throughout the year if:

• you are not often outdoors, such as the frail or housebound 
• you live in a care home
• you usually wear clothes that cover up most of your skin when outdoors

Some news stories have circulated suggesting that vitamin D can reduce the risk of coronavirus. 

There is no evidence that this is the case. 

The AESAN (Spanish Agency for Food Safety and Nutrition) confirms on its website that: "AESAN reminds consumers that food supplements are foods whose purpose is to supplement the normal diet. These products cannot attribute properties to prevent, treat or cure a human disease, nor refer to such properties at all. There are no food supplements that prevent, treat or cure coronavirus infection and therefore there cannot be any product on the market with such claims.”

Dr Narvaez concludes:“Until time that lockdown regulations are relaxed, it is important to make the most of valuable sunlight by standing by open windows or balconies at home for 15 minutes a day - exposing arms and legs without using sunscreen. People who need to go outside for essential shopping, work or to take their dog for a walk can take advantage of these short times outside to allow the body to absorb some sunlight.”