The Vitamin (that is not a vitamin) in the time of COVID
Please note: because we feel that the contents of this blog may be so important, we have decided to republish it including some small editing of the original, along with some additional text. All such text is shown in italics.
In the last couple of weeks, several sources have suggested that levels of vitamin D may play a part in the host defence against the more severe consequences of infection with SARS-Cov-2 coronavirus. At first we thought this might only be a theoretical idea, not least because there have also been published reports which dispute it. It’s certainly widely recognised, though, that healthy levels of vitamin D can help support immune systems, but actually vitamin D levels might help explain one or two of the many anomalies in respect of how this novel infection is manifesting.
But careful consideration of this vitamin may open a window on a simple way of protecting ourselves against the worst of this disease - and simple protection against infectious agents is something that we in Moxafrica are always interested in.
It seemed to us that it would be easy to establish whether there was anything to these claims: vitamin D levels could simply be tested in all those admitted to any hospital (whether COVID-19 positive or otherwise), and levels compared in particular in respect of the progression of severities of disease in COVID confirmed cases to see whether there were correlations between levels of Vitamin D and severity of disease progression.
And then we came across a study that has done almost exactly that and (rather surprisingly) it’s been out there since early April largely unreported.
A total of 212 patients who were admitted to three hospitals in South Asia with confirmed SARS-CoV-2 infections had their blood levels of Vitamin D checked on admission (technically speaking, this was their 25-hydroxyvitamin D [25(OH)D] levels which is the gold standard for measuring Vitamin D). They were then tracked through their treatment.
The total number of cases reviewed certainly wouldn’t satisfy an epidemiologist (i.e. more research would be necessary to draw any definite conclusions). But if what the study reports is even half right they most certainly should have stimulated more research by now given what they imply. This is because they clearly suggest that both deficiencies and insufficiencies of vitamin D significantly increase the likelihood of developing ‘severe’ (i.e. with respiratory distress) COVID-19 disease as opposed to remaining a ‘mild’ case nearly nine-fold. What’s more, they appear to make it nearly twenty times more likely for the condition to become critical (i.e. with respiratory failure). Looking at it from a simpler perspective, sufficient levels of Vitamin D (defined in this paper as more than 30 ng/ml) might provide significant protection from the more serious ravages of this disease, whilst ‘deficient’ levels (defined as less than 20 ng/ml) may be a significant risk factor.
Adding a bar chart (credit to Grassroots Health for this) and discussing some of the recorded percentages may help better illustrate this. Of those with ‘normal’ levels (the green sections in the above bar chart) 86% of all of them had only ‘mild symptoms (with only 8% of them developing severe or critical symptoms); meanwhile of those defined having ‘insufficient’ Vitamin D of less than 20 ng/ml (the red sections) only 1% of them maintained mild symptoms while 73% of them developed either severe or critical disease.
We should quickly add that this paper (in ‘Social Science Research Network’) is currently a pre-print version published before any peer review has been undertaken - but the same limitation can equally be said of the majority of more-than 7,000 papers on COVID that are currently in process of peer-review but which have already been hastily published many of which are being jumped on by the media.
What anomalies might this explain?
It's important first of all to understand that Vitamin D is a misnomer because it's not actually a vitamin at all. It’s a fat-soluble prohormone that can normally be produced by the body through sun exposure but which can also be absorbed from certain foods.
With that in mind these data may help explain the worryingly disproportionate number of deaths in black and Asian and minority ethnic (BAME) COVID cases being reported across the northern hemisphere. Of course there may be other complex factors involved, but it’s worth noting that vitamin D is known to be 5 to 10 times harder to be naturally absorbed from sunlight and then converted in darker skinned people.
It may also help explain the emerging data on the higher proportion of obese people who develop more serious disease because it’s also well known that it is much harder for Vitamin D to be absorbed in the obese, no matter how much is taken in from food or sun exposure. This is because the 25(OH)D prohormone is fat soluble, and so gets easily diverted into fat cells rather than ending up circulating in the blood stream.
Elderly people are also known to be of much higher risk of severe disease and death from COVID-19, and they also are prone to vitamin D deficiency because (for many reasons) older people tend to avoid sunlight exposure, and because their skin creates less vitamin D in sunlight anyway.
It even explains the curiosity that death rates have been higher in southern European countries than in Scandinavian ones since Scandinavian countries more actively promote Vitamin D supplementations during winter and have been fortifying foodstuffs with it for decades.
So what does this mean?
Well, while a vaccine is being held out as the best hope by many governments, and vaccine research may be taking place at pace all over the world (with tens of billions of dollars being thrown at it), it’s impossible for these necessary clinical studies to be properly completed to see a vaccine actually being rolled out at safe scale in less than a year. What’s more, it’s far from certain whether an effective long-lasting vaccine is even possible. Either way, there will be no vaccine available in this calendar year, so the populous Northern Hemisphere (which has already taken its first battering from this virus) could be in for a very tough winter indeed, as immunity levels generally naturally decline as sunlight reduces and the virus re-emerges.
This risk is rendered even more serious by the potential impact of any normal seasonal flu epidemics which by themselves can take health services in midwinter to the brink of collapse.
It seems logical, therefore, that all of us should do all we can to strengthen our immune systems any way we can, and it’s equally logical that bolstering our Vitamin D levels could help this. It certainly won’t do us any harm – at the same time, in fact, it may help protect against severe COVID-19 disease and seasonal flu at the same time.
But what’s also important to appreciate is that measurable signs of raised vitamin D levels take about 60 days of supplementation to materialise. So if you have any concern about your immunity, or indeed about your relative risk from an infection with this coronavirus, we would consider it a good idea to get a blood test for Vitamin D if you can.
The range of Vitamin D levels which are considered to be 'normal' is huge, incidentally (12-55 ng/ml). Supplementation is normally only recommended if levels are near the bottom of this range, but it is important to also realise that this recommendation was developed for bone health and not for immunity.
The results of this study suggest that if levels are found to be less than 30ng/ml, then long-term supplementation through the summer, continued through the winter, would be a very good idea indeed. Of course, we would advise you to adhere to whatever your doctor might recommend, but since there is still no effective treatment for this disease, and no vaccine likely until after next winter at the earliest, we doubt if she/he would disagree with a course of supplements along with some pleasant moderate spells in the sunshine (being extra careful not to burn of course). And we would further suggest that the target level should be 60ng/ml.
Doctors are as acutely aware of the risks of this disease as any, not just to those most vulnerable to it but also to existing health service - and frankly (given that they are at the front line in terms of constant exposure risk) if they've been doing their own homework, we'd be surprised if they weren't doing something similar themselves already.
Finally, because of the emerging gravity of this issue, we finish by advising that we will very soon publish a second blog examining the underlying issues.