I live in Michigan, where we do not get a lot of sun in the winter. I have been taking supplements for just over a year now. Nine months ago, I had my levels checked and I was at 39. I recently had them checked again after taking 2000 IU's of Vitamin D-3 for nine months, and I was at 41. My goal is to get into the 60 or better range, so I am taking 5000 IU's of Vitamin D-3 a day now. The hospital lab charges hundreds of dollars for the test, however. Has anyone here tried the test you can order, via, mail, for measuring D levels? It is just $65.00 and comes with instructions for use. I guess you mail in your sample after getting one from a finger poke.