Result: not been sick more than a day or two for fifteen years. And rarely, once or twice a winter.
One exception, during covid I had it and it lasted five full days at medium intensity, then went away permanently.
This is not a “placebo effect” at all, was like turning on a light switch, immediate results. During the winter I heard about it, I’d been sick for almost three weeks straight, couldn’t shake it. Naysayers look silly in my opinion, or are perhaps an exception I mentioned above.
I raised vitamin D intake in winter, I take betaglucans and if I feel like I am starting to get under the weather I take 2-3g of vitamin C per day.
Since we started that, no colds or flus for me or my wife and we have a kindergarten kid.
I still was sick all the time. That combination of not enough sleep (kids crying in the night etc.), work stress and insane amount of viruses from nursery is killer.
Not well known but there are people who simply can not absorb D thru the gut. A high school friend is one. Shouldn’t discourage the 90%+ who can benefit because of exceptions.
I got sick so often it limited a lot my general life: I stopped practicing sports regularly and started being very careful with sleep(sleep deprivation likely increased the chance of infection), because I knew if I did not lead a perfectly balanced lifestyle I would get sick. I am quite upset I stopped running 15km per week, even with snow. I never fully went back to it, due to fear of getting sick, and having to take care of toddlers while being feverish or nauseated.
In those years I think I was not disease free more than 3 months at a time. In a year where many people decide to not have children, it does not help the cause of having children seeing other parents suffer so much, in those early years. I have non parent friends that get sick after meeting us, resenting meeting us and asking if we are sick, because they spent all the night in the bathroom or with fever. Fortunately it feels we are already immune because we are not sick very often anymore.
Does running long distance increase the chance of getting sick?
So if I am exhausted of a run and cannot rest or sleep, it is almost sure I get sick soon after. Just my experience.
My oldest starting preschool was one of the worst times in my life. We were sick from august to december, then january to may. Dreadful.
It got better. My youngest is 3 now and is ahead of where my oldest was due to having 2 older siblings importing illnesses for several years, and this year we finally were mostly not sick all school year. Which is to say, we were probably closer to the 15 days "materially sick" mark. I say materially sick to mean, definitely sick, though perhaps not taken out of school (due to not technically being outside of the health exclusion policy, and sometimes I only realize they were "materially" sick instead of just "passably sick given kids will basically have a lingering cough from august to may").