Interesting thing... Vitamin D is one of those things that, when vitamins come up on HN, you will often hear the refrain that "it's the one vitamin that large numbers of people are actually deficient in and ought to supplement."

I've heard that many times over the years and I have taken a Vitamin D supplement on and off (more off than on) over the years.

When this COVID-19 thing first hit, I had a physical scheduled (by chance) just about the same time, and I'd heard about this Vitamin D / COVID-19 connection, so when I went in for my physical, I asked my doctor to order a Vitamin D test as part of my bloodwork.

As it turns out, I was indeed very deficient in Vitamin D. I started taking 4000 IU a day and it's had a noticeable impact on my overall sense of wellbeing. It could, of course, be placebo effect even so. And I have no particular reason to think that it will make any difference one way or the other in terms of me getting COVID-19. But I thought it was worth pointing out one more anecdote that suggests that the old "Vitamin D is worth supplementing" refrain might just be true.

If you're in doubt, and it's an option, do what I did... just ask your doctor to run a Vitamin D test next time you go in for a checkup / physical.