Here’s an article from Mercola strongly recommending Vitamin D as both a means to prevent a Covid-19 infection and as a way to greatly minimize the impacts if you do get infected by the coronavirus. The article then wanders a bit off topic and into more esoteric things in its second half, but the first half on Vitamin D is easily understood and, if you decide to implement it, does not require any type of prescription medicines.
Update – since I wrote this article back in July, additional studies (in more mainstream publications) have been released supporting Vitamin D as a way to reduce your risk of coming down with the virus. The evidence remains weak rather than 100% certain, but the balance is moving further in favor of considering some Vitamin D.
Mercola is a controversial website that features many non-mainstream medical views and treatments, so I tend to not-trust and always verify everything they say. But, although I start of with skepticism, I often find their content to be better supported than its non-mainstream perspective would suggest.
On the face of it, their coverage of the correlation between Vitamin D levels and Covid-19 outcomes seems moderately convincing, and has plenty of links to sources to support their recommendation. Of course, it is necessary to evaluate the sources, and also match the overall recommendations with other opinions about appropriate levels of Vitamin D dosing and knowledge of possible side-effects of high Vitamin D supplementing.
It seems in this case, the Mercola article is closely based on this other article. The other article in turn collates other information which seems quite persuasive.
This chart in particular makes for a very obvious correlation between Vitamin D levels and Covid-19 mortality rates, although the original chart this was redrawn from is not quite so clear.
The original chart is from this article.
Here’s a good general article covering Vitamin D to put the Mercola recommendation into context.
My feeling is that if it is safe to take more Vitamin D than normal, perhaps it makes sense to do so. Vitamin D supplements are inexpensive – Amazon has several products offering a year supply for under $15. Costco has a similar product range and pricing.
This leads to the question – how much should you take? The Medshadow article linked to above observes that the Institute of Medicine believes 600-800 IU for adults and 800-1,000 IU for seniors over 70 is sufficient for most people, and bases this on a level of greater than 20 ng/mL of Vitamin D as measured by the 25(O)D method. But this is a recommendation for normal people, in normal times. It is not a recommendation for our very unusual times and the specific threat of the coronavirus.
The Vitamin D council – perhaps unsurprisingly – recommends more as a general level of dosing, and suggests 5,000 IU a day to get to a 50 ng/mL (125 nmol/L) level of Vitamin D. Offset against this, the IOM says levels over 50 ng/mL may be a concern, and suggests 4,000 IU a day as the maximum limit.
This article looks at “how much is too much” and the answer is inconclusive but seems to be very much higher than the preceding recommendations. This article says that 7,000-15,000 IU of Vitamin D a day is safe, even if given for a full year. This article is more cautious and recommends limiting your intake to 4,000 IU a day. Here’s one more perspective from another reputable source.
Mercola says that 8,000 IU a day will get you to 40 ng/mL, and if you are underweight, 6-7,000 IU would be enough. Mercola suggests a target level of 60-80 ng/ML, but says anything above 30 ng/mL will have dramatic benefits in terms of Covid-19 risk.
The charts above show a major reduction in fatality rates when you go over 20 ng/mL (ie 50 nmol/L as shown on the chart).
This website gives side effect, interactions and normal dosing information.
My take-away from all of this is that because it takes time for Vitamin D to build up in your system (it has a half-life of 25 days) it probably makes sense to take higher doses for a week or two before reducing to a maintenance level dose subsequently.
Also, for the same reason – time to build up the Vitamin D, this is something you should start taking now as a preventative medicine, rather than something you don’t need to take until after you’ve come down with Covid-19.
In my case, there is already 400 IU of Vitamin D in my daily Costco multi-vitamin tablet. I’ve decided to take 5,000 IU extra a day for a couple of weeks and then perhaps drop to 2,500 IU extra a day from then and onwards. 5,000 IU seems to be considered safe in all the literature, and 2,500 is probably on the low side of the scale in terms of taking enough extra Vitamin D to actually have an impact on your Covid-19 susceptibility. Particularly if you’re older or overweight, a case could be made for considerably more than 2,500 IU/day.
As always, please remember, I’m not a doctor. I’m merely reviewing the literature and sharing my own interpretation and actions. If it is convenient for you to discuss this all with a doctor – truly discuss, rather than just get a standard automatic response – then that would of course be very helpful.