I’m delighted to report that I have successfully warded off some kind of illness — a cold or the flu — with Vitamin D. Or so I have good reason to believe.

I began to get sick on Tuesday afternoon. My throat was sore and itchy, my nose was stuffy and sneezy. I was feeling icky. When I woke up around 2 am on Wednesday morning, I was sure that I was coming down with something. I felt downright miserable. In every other case when I’ve felt that bad, I’ve gotten sick.

I took some extra Vitamin D on Tuesday evening, then I took a large dose on Wednesday morning — about 15,000 IU, I think. (If I recall correctly, up to 50,000 IU is safe.) I also sat in the sun for a good while that Wednesday morning, with lots of skin exposed. I also spent about two hours in the sun that afternoon. By Wednesday afternoon, I felt perfectly fine.

A few months ago, Paul and I took a hefty dose of Vitamin D when we both developed scratchy throats. Neither of us got sick. However, in that case, the prospect of a cold/flu wasn’t quite so obvious as in my recent brush.

So, despite spending three days per week at Boulder for the past few months — including through a particularly nasty flu season — I did not get sick. In the past, I’ve gotten sick at least once per winter. Last year, I got sick three times, once quite badly. This fall, winter, and spring, I’ve been perfectly healthy — even though I’ve been far less concerned to avoid sick people than I have in the past.

My personal findings integrate nicely with what I’ve read on the effects of Vitamin D, most notably this medical report: Epidemic Influenza And Vitamin D.

In addition, I’ve had no allergies this year whatsoever. A few years ago, I developed allergies for the first time around late March. They mostly disappeared for a few years. Last year, I had them very badly for a full month. I was miserable. This year, happily, nada.

Of course, certainty in such cases requires attention to long-term trends. However, I do think the preliminary data looks darn good.