Could vitamin D play a role in coronavirus resistance?

Andrew Thomas says community pharmacists offer support and trustworthy advice so their patients can make informed decisions for their health and wellbeing…

The mounting evidence surrounding the vital role of vitamin D in
supporting the health of the nation throughout the coronavirus
pandemic has been widely reported by the media, with evergrowing
demands being made within government for a formal announcement on the role the supplement can play in our drive to improve immunity.

And yet, there is seemingly still a great deal of confusion regarding who will benefit from supplementation, how much should be taken and what levels we should be chasing. This means it’s a vital time for community pharmacists to offer their customers muchneeded support, providing a source of trustworthy information so that patients can make informed
decisions for their health and wellbeing.

When it comes to the role vitamin D can play in our body’s ability to better resist disease, here are the key factors to know.

Vitamin D and Covid-19

Vitamin D plays an important role in immunity, with a growing number of clinical studies specifically linking deficiency to a decline in immune response for respiratory viral infections. Whilst it has been necessary to contain the virus, the UK ‘lockdown’ has denied vital natural vitamin D
production at a time when we would normally be building levels – after an annual vitamin D ‘starvation’ since October.

As I write, political voices are being raised from all parties for a formal assessment of vitamin D’s importance at this time. As a result, Public Health England (PHE) is carrying out a rapid review of recent evidence relating to vitamin D and the prevention of acute respiratory tract infections, particularly the prevention and treatment of Covid-19, for the
Scientific Advisory Committee on Nutrition (SACN) to consider at its next meeting.

There are now two large-scale clinical trials operating within the international scientific community to investigate the efficacy of vitamin
D against Covid-19, with the most recent being announced in early April.

It is unknown whether optimal vitamin D supplementation could be used as an acute treatment to Covid-19, but this is asking the wrong question. We should be asking whether our bodies are as robust as possible and are we
able to resist and better manage the unpleasant, and in some cases unfortunately fatal, experience of viral infections?

Daily maintenance dosage for every 25kg of body weight is 25mcg of vitamin D
Vitamin D and BAME community

It has been repeatedly reported that a disproportionately high number of individuals who are from black, Asian, and minority ethnic (BAME) communities have died from Covid-19.

Comparing the blood samples of 1,300 adults on the UK Biobank health-monitoring programme (of which 580 tested positive for COVID-19), a new study found that vitamin D levels among white people were around 53 per cent higher than those among people of BAME backgrounds.

Vitamin D deficiency is more prevalent in people with darker skin due to a natural barrier (known as melanin) towards the UVB rays needed to penetrate the skin. Melanin competes with the vitamin D receptors in the skin, meaning that darker skin types allow less UVB to enter the skin and consequently produce less vitamin D. This is useful for high UVB exposure nearer the equator but problematic here in the northern hemisphere.

These findings may also help to explain disproportionate levels of infection among the BAME community – and can certainly provide relevant information for customers when considering whether they feel they ‘need’ to supplement.

Tailored supplementation

Scientific writer and nutritionist, Ben Brown, recently reminded us that a 400 IU dose (the dosage recommended by PHE) “isinadequate to raise blood levels to sufficiency in deficient, vulnerable people and it is arguable that a
deliberate failure to acknowledge potential benefit related to Covid-19 not only misses, but dismisses an important opportunity to improve public health”.

Considering the latest research, together with BetterYou’s decade of testing and supplementation, evidence suggests that a supplementation dosage related to body mass is required, instead of a single dosage level for all.

The concept is relatively simple. As we expose ourselves to the sun, we generate vitamin D. The more skin exposed, the greater the level of production. During this exposure, melanin is produced in the skin to reduce vitamin D conversion. A small child will expose less surface area and require less time exposed to the sun than an adult male. The child will produce less vitamin D as it requires less.

As a rule of thumb, a daily maintenance dosage of 25mcg (1000 IU) of vitamin D for every 25kg of body weight is advisable. 400 IU is a suitable maintenance dosage for an infant or toddler, but for an adult woman living in the UK we should be recommending 2000 IU, and for an average male, 3000 IU.

This is for maintenance only. To reverse a deficiency, we would advise a brief period of a higher dosage, which would be determined based upon specific blood levels.

What ‘optimal’ looks like

When it comes to the optimum blood level there is also a healthy debate. The official measurement for insufficient serum levels is under 50nmol/l and for deficient is under 25nmol/l. However, there is no guidance for what would be considered optimal.

A review of disease incidence and associated vitamin D levels by Garland and Baggerly clearly illustrated that an optimal serum level would be between 100-150 nmol/l (40-60ng/ml), a level at which they suggest provides optimum defense against several associated auto-immune diseases.

In conclusion, there is no convenient cause and effect, and no ‘quick fix’ solution for Covid-19. There is, however, evidence to suggest that vitamin
D has an indirect benefit as it plays a powerful role in our immune health and auto-immune diseaseresistance. One thing we can at least all agree on, is that the importance of vitamin D levels within our society has never been greater than now.

Andrew Thomas, founder and MD at BetterYou.