As the COVID-19 pandemic persists, so, too, does research into potential health aids. SPR scours new indications of vitamin D’s positive implications, and why intake of the nutrient is being increasingly encouraged.

The merits of vitamin D have long been remarked upon, but in recent weeks and months the scope of the nutrient’s benefits has been further broadened – with it poised as a possible support in the battle against COVID-19.

New research has surfaced regarding the advantageous potential of its intake; in particular, the report ‘Vitamin D Deficiency in Ireland – Implications for COVID-19. Results from the Irish Longitudinal Study on Ageing (TILDA)’ has highlighted vitamin D’s critical role in preventing respiratory infections, reducing antibiotic use, and boosting the immune system’s response to infections.

The Expert Insight

Shedding light on the results garnered from the research, Professor Rose Anne Kenny, Principal Investigator of TILDA, explained, ‘We have evidence to support a role for vitamin D in the prevention of chest infections, particularly in older adults who have low levels. In one study vitamin D reduced the risk of chest infections to half in people who took supplements.

‘Though we do not know specifically of the role of vitamin D in COVID infections, given its wider implications for improving immune responses and clear evidence for bone and muscle health, those cocooning and other at-risk cohorts should ensure they have an adequate intake of vitamin D. Cocooning is a necessity but will reduce physical activity. Muscle deconditioning occurs rapidly in these circumstances and vitamin D will help to maintain muscle health and strength in the current crisis.’

How is Vitamin D Produced?

Vitamin D is produced in the skin by exposing the body to just 10-to-15 minutes per day of sun. It can’t be made in the winter, and the amount that we make in the summer depends on how much sun we get, weather and other factors. Even in the summer, attaining a sufficient amount of vitamin D can pose a challenge due to cloud cover, rainy weather, and a lack of sunshine.

The good news is that deficiency can be remedied by adequate intake of foods and by supplementation. In fact, vitamin D is readily found in foods like eggs, liver and oily fish – such as salmon or mackerel – as well as fortified foods, such as cereals and dairy products.

Who is Most at-Risk of Vitamin D Deficiency?

People who get little sun exposure or eat inadequate amounts of fortified foods are most at-risk, especially those who are currently house-bound or confined to their homes. Other people who fall into the high-risk category are those who are obese or physically inactive, and those that have asthma or chronic lung disease.

Vitamin D is available without prescription. What is needed now is for people to increase their vitamin D intake, especially as supplementation is low across the nation, and particularly low in men.

 Dr Eamon Laird, Research Fellow in Medical Gerontology and co-author of the report, commented further on the newly-released data, saying, ‘These findings show our older adults have high levels of vitamin D deficiency which could have a significant negative impact on their immune response to infection. There is an even larger risk now of deficiency with those cocooning or confined indoors.

‘However, vitamin D deficiency is not inevitable – eating foods such as oily fish, eggs, vitamin D-fortified cereals or dairy products and a daily 400 IU (10ug) vitamin D supplement can help avoid deficiency.’

What is the Recommended Intake for Vitamin D?

TILDA researchers have recommended that adults over 50 years of age should take supplements – not just in winter, but all year-round if they don’t get enough sun. Those who are cocooning at present should also take supplements.

Vitamin D: What in the World?

A global perspective of the role of vitamin D throughout the pandemic has additionally been produced; pointing towards a correlation between severe deficiency of the nutrient and mortality rates.

Led by Northwestern University, the research team conducted a statistical analysis of data from hospitals and clinics across China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the UK, and America.

The researchers noted that patients from countries with high COVID-19 mortality rates, such as Italy, Spain and the UK, had lower levels of vitamin D compared to patients in countries that were not as severely affected. However, this doesn’t mean that everyone – especially those without a known deficiency – needs to start hoarding supplements, the researchers caution.

 ‘While I think it is important for people to know that vitamin D deficiency might play a role in mortality, we don’t need to push vitamin D on everybody,’ explained Northwestern’s Vadim Backman, who led the research.

‘This needs further study, and I hope our work will stimulate interest in this area. The data also may illuminate the mechanism of mortality, which, if proven, could lead to new therapeutic targets.’

By analysing publicly-available patient data from around the globe, the team discovered a strong association between vitamin D levels and cytokine storm – a hyperinflammatory condition caused by an overactive immune system – as well as a parallel between vitamin D deficiency and mortality.

Not only does vitamin D enhance our innate immune systems, it also prevents our immune systems from becoming dangerously overactive. This means that having healthy levels of vitamin D could potentially protect patients against severe complications, including death, from COVID-19.