I found that out the hard way. I couldn’t get well from pneumonia, had no strength in my legs and found out I was seriously deficient in vitamin D. Immediately after I got on the heavy regimen, I got better.
I now take 2000 daily.
Yup. I was getting 1-2 bouts of bronchitis every winter. I read the article in post #4 and started taking an increased dose at that time and have moved up to 4,000 IU daily presently.
I haven't been sick since. Period!
I do not Jog. I do not Hike. I do not Walk. There’s WEATHER out there, you know. I exercise at home with the AC turned up to Meat Locker. And yes, even living in Hawaii, I take D daily...