Public Health England is working with NICE on the review and has asked the Scientific Advisory Committee on Nutrition to carry out a separate report.

Vitamin D is extremely necessary– Public Health England issued guidance in April advising everyone to take the supplements.

A trial being led by Professor Adrian Martineau of Queen Mary University in London is investigating how certain lifestyle factors – including vitamin D levels – affect susceptibility to the virus.

'Vitamin D could almost be thought of as a designer drug for helping the body to handle viral respiratory infections,' he told The Guardian last night.

A review from the University of Surrey, which was published in the British Medical Journal last month, found that vitamin D should be seen as part of a healthy lifestyle but not as a 'magic bullet' – because the evidence was not yet clear.

Dr Lee Smith, who led Anglia Ruskin's study, said: 'It has been shown to protect against acute respiratory infections, and older adults, the group most deficient in vitamin D, are also the ones most seriously affected by Covid-19.

A previous study found that 75 per cent of people in institutions, such as hospitals and care homes were severely deficient in vitamin D.'

A Public Health England spokesman said: 'NICE is working on a rapid evidence summary on vitamin D in the context of Covid-19 with support from Public Health England. This report will be published in due course.'

The NHS says the general consensus is levels of below 25nmol/L — the equivalent of 10ng/ml — in the blood indicate vitamin D deficiency.

This is thought to be the equivalent of taking around 10 micrograms of vitamin D a day. The Institute of Medicine — a US health advisory body — states levels below 20ng/ml (50nmol/L) is a deficiency.

Large doses of vitamin D can be dangerous, with anything above 100 micrograms to be taken only under medical supervision.

VITAMIN D DEFICIENCY COULD RAISE COVID-19 DEATH RISK' FOR BAME PEOPLE

BAME people may face a higher risk of dying from the coronavirus because they are more likely to have a vitamin D deficiency, scientists claim.

The pandemic is seeing higher rates of people from black, Asian and minority ethnic backgrounds dying if they catch the coronavirus. The reasons are still unknown and will likely be numerous and complicated. But some experts think a lack of vitamin D may play a role.

People with darker skin need to spend more time in sunlight in order to get the same amount of vitamin D as a person with lighter skin.  

For this reason, the NHS suggests people with an African, African-Caribbean or south Asian background could benefit from taking a daily supplement throughout the year.

Vitamin D may have a protective effect against severe coronavirus by regulating the immune system, and deficiencies of it have been linked to other respiratory viruses. However, the largest study to investigate the link between BAME, Covid-19 and vitamin D in a UK population found no proof.

William Henley, a professor of medical statistics at University of Exeter, told MailOnline the link is worth exploring.  He said: 'Preliminary research suggests vitamin D levels may also impact on the risk of people suffering from severe COVID-19 infections.

'In the UK and northern European latitudes, vitamin D deficiency is a public health concern because ultraviolet B (UVB) radiation is of insufficient intensity for vitamin D synthesis during winter months.  

'This is a particular concern for people with dark skin, such as those of African, African-Caribbean or south Asian origin, who will need to spend longer in the sun to produce the same amount of vitamin D as someone with lighter skin.

Our Liquid Vitamin D is essential for maintaining blood calcium and phosphorus levels to promote healthy growth and remodelling of bone. Vitamin D is also thought to be involved in the following functions:

• Promotes calcium absorption in the intestines
• Proliferation, differentiation and apoptosis of cells
• Affects neuromuscular function and inflammation
• Positive effects on the immune system

Vitamin D is a fat soluble vitamin and thus requires dilution in an oil for optimal absorption. Our vitamin D3 is super concentrated and dispersed organic hemp seed oil to enable maximum intestinal absorption.

1 drop of D3 delivers (5mcg) cholecalciferol 50% of the EU RDA. Optimal dosing is with breakfast on food or in juice.