In June of 2009, my vitamin D level was checked. It was 19. I had been supplementing with 2000 IU of vitamin D daily for a couple years. I had also been bothered by Seasonal Affective Disorder (SAD) during the winter for years, leaving me feeling like I was holding my breath all winter, trying not to think about the irrational desperation that was a constant feeling all winter long, while I waited for the sun to reappear in the spring. 2000 IU of vitamin D had not brought my level up to even minimum accepted levels. Because it was summer, I concentrated on getting more sun, which always helps, but is impossible to get at least six months a year here. Once autumn started, I began taking 5000 IU daily. For 3 weeks I took 10,000 IU 5 days per week and then went back to 5000 daily.
In June, 2010, I was tested again. My level had risen from 19 to 38 in one year after taking what was once considered a very high dose. My doctor was pleased and advised me that it should be kept in the 35-55 range, so I have no room to let it slip. He also advised me to take 5000 IU once per week during the summer, as I usually stop it altogether during the summer.
It isn't easy to raise your D level and almost impossible on low doses of D. Between one half and two thirds of the population that has been tested have tested low for D levels. Almost all thals tested are low. Do yourselves a favor and get tested if you haven't, and correct the level if needed. The difference it makes to your immune system and mental well being are quite noticeable. We are having one nasty winter and at no point have I felt that desperate feeling. I also find that the couple colds I've had the past two years have been mild and lasted only 3-4 days. If only it helped with my allergy to dust.