Vitamin D could help play a key role in the prevention and treatment of COVID-19, say health experts.
The prohormone has been studied in the treatment of other respiratory diseases, offering the potential to boost antiviral immune responses and dampen harmful inflammation.
Links have been established between a deficiency of vitamin D and critically ill COVID-19 patients – and a deficiency noted in many populations most at risk from the virus, such as the BAME community.
However, further research is needed to establish whether vitamin D might have a role in reducing risk of COVID-19, or in improving clinical outcomes when administered to patients experiencing COVID-19 symptoms.
A panel of world-leading experts took part in an online discussion, Seeing the Light, organised by pharmaceutical manufacturer Thornton & Ross – part of the STADA group – to examine how vitamin D could play a role in the fight against COVID-19.
A literature review by the National Institute for Health Care Excellence (NICE), published at the end of June, found while there was no evidence to suggest taking vitamin D could prevent someone catching COVID-19, it was important to follow government guidelines on supplementation to maintain bone and muscle health.
In the summer months, around 80-90% of the body’s daily requirement of vitamin D can be obtained through exposure to the sun, but in autumn and winter a supplement may be needed – particularly in the event of a second wave later in the year. People with darker skin – for example those from black or Asian ethnic backgrounds – or individuals with little exposure to sunlight through shielding should consider taking 400IU (10 micrograms) daily to avoid a deficiency.
Prof Martin Hewison, from the University of Birmingham, said favourable research had suggested links did exist between a deficiency of vitamin D and COVID-19 and other respiratory diseases. Poor levels of vitamin D can impair the function of the immune system and the lungs. It also helps to kill bacteria in conditions such as TB and sepsis.
He said: “There are benefits of vitamin D supplements for respiratory infections. It is an ideal molecule for diseases such as COVID-19 as it helps combat infection, whilst also being a potent anti-inflammatory agent.
“However, while there has been a lot of perfectly logical speculation this is a complex issue and important aspects need to be established, such as the optimum levels of vitamin D to protect against COVID-19, when is the best time to introduce a supplement and whether it would affect other drugs being used to treat the virus.
“In many ways, it has taken a pandemic to bring vitamin D into the spotlight and to bring about an open discussion about its potential benefits.”
David Thickett, a professor of respiratory medicine at the University of Birmingham, said if trials proved it was beneficial, administering a vitamin D supplement could prove to be a simple and inexpensive treatment for COVID-19 patients.
Vitamin D deficiency was a known risk factor for developing critical illness, he said. In a sub analysis of a large trial, critically ill patients with severe deficiency who received a supplement had a lower mortality rate – this is currently being tested in an ongoing trial.
He said tests carried out specifically on hospitalised COVID-19 patients revealed they had noticeably lower levels of vitamin D than hospital staff of a similar age and ethnicity.
COVID-19 patients, he concluded, may benefit from taking a supplement as part of clinical trials, although the absorption of the drug may not be quite as anticipated so carrying out a dosing study would be vital. If trials proved it was beneficial, administering a vitamin D supplement could prove to be a simple and inexpensive treatment for COVID-19 patients.
The webinar took place on July 9th when more than 400 health care professionals dialled in to participate in the discussion. Afterwards, 85% said that despite the limited current evidence, they felt using vitamin D could be beneficial in the fight against COVID-19. And 84% said the event had increased their understanding of the role vitamin D could play in treating COVID-19. Almost two thirds (60%) said the discussions would impact on their daily practice.
 Trial conducted by Vidalize