Vitamin D – Hype or Magic bullet against Covid-19?

As with most aspects of science, there is typically the protagonist and the antagonist. One of the great examples here is that of supplementation.

Image source: Michele Blackwell, Unsplash

The argument used by many people in the conservative medical world is that if you consume a good diet, there is no need to supplement because you are not deficient in any of the vitamins, minerals and trace metals that you will obtain from natural, nourishing food.

Although, I totally agree that eating good quality food is an important principle of good health, there are a number of factors in our modern world pointing to the need for supplementing a healthy diet.

A significant proportion of the population have very sedentary jobs where they are typically indoors and not exposed to the sun. Also, for those of us living in Australia, we know too well that this is the skin cancer capital of the world. Thus, our exposure to UVB radiation, a major natural source of Vitamin D, is reduced by avoiding the sun.

Thus, it is estimated that a third of the Australian population is vitamin D deficient with levels below 50 nmol/l. There is also a well-established link between low vitamin D and osteoporosis, cardiovascular disease, cancer, type 2 diabetes, depression, multiple sclerosis and asthma.

A number of other studies have shown a direct link with low vitamin D and susceptibility to viral and bacterial respiratory infections. Since the advent of the coronavirus pandemic there have been a number of studies suggesting a link between vitamin D deficiency and COVID-19, COVID complications and death from COVID.

A recent study published in the journal Scientific Reports from Trinity College and the University of Edinburgh in the UK has reinforced the link between vitamin D deficiency and COVID-19.

It has been estimated that there are over 100 genes that determine vitamin D levels in your body. The researchers in this trial examined genetically predicted vitamin D levels along with exposure to UVB radiation which promotes vitamin D absorption from the skin and thus assists in generating normal Vitamin D levels in the blood stream.

This study involved around half a million individuals living in the UK and found that vitamin D concentration was threefold higher for UVB predicted vitamin D levels compared to the genetically predicted levels.

They also found that UVB radiation prior to developing COVID-19 was strongly and inversely associated with hospitalisation and death.

I have been suggesting to all of my patients since the start of the pandemic that they should maintain a vitamin D level around 100 nmol/L because of a number of papers suggesting these protective benefits. I also suggest at least 15 minutes daily in the sun during the non-burning times before 10AM & after 3PM. Vitamin D supplementation is extremely inexpensive but unfortunately the levels in the blood stream are quite variable. Interestingly, the darker your skin, the less vitamin D you absorb. This may be also linked to the fact that people with darker or olive skin appear more susceptible to COVID, COVID complications and COVID death.

Another major factor here that is not being highlighted by most health authorities is the link between insulin resistance and COVID. Again, people with darker or olive skin are almost all insulin resistant and therefore more susceptible to COVID.

I would strongly suggest the next time you are having a blood test, ask your doctor to check your vitamin D levels and unless you have naturally high levels placing you around 100 mark, I would be supplementing with anywhere between 2000–5000 international units daily.

It is important not to overdose on vitamin D as levels beyond 200 have been found to be harmful but the evidence strongly suggests that vitamin D deficiency is the real issue and there is a clear association with a variety of diseases. So, is Vitamin D supplementation hype or a magic bullet? As with most aspects of medicine, I believe it is neither but certainly an important component of maintaining good health & not only giving some degree of protection against COVID.