Oprah did it. She published one of the most succinct and up-to-date articles about vitamin D on the internet. See article at: http://www.oprah.com/health/Why-Knowing-Your-Vitamin-D-Levels-Might-Save-Your-Life/1. However, she states that 5000-6000 IU's daily for a couple of months can resolve vitamin D deficiency, with 2,000 IU's daily thereafter. This may be true for some people but not for all. I know of people who took more than a year at 14,000 IU's a day to get their levels just to 60 ng/ml, and this doesn't even take into account a known 20-30% error in vitamin D lab tests.
After correcting for known lab error in the vitamin D test methods, 60 ng/ml is really 48 ng/ml. According to John Cannell, M.D., the body uses 50 ng/ml per day (approximately 65 ng/ml before lab error correction). At a true level of 48 ng/ml per day, this would be a deficit of 2 ng/ml per day. I know someone whose chronic fatigue and bladder pain symptoms started to return when she let her level fall from 69 ng/ml to 60 ng/ml. I also know of a blogger on the DoctorsTV website who has had to take 100,000 IU's a day to get her level to rise. Everyone is different, so be careful of blanket recommendations. Get tested to get your baseline, and keep getting tested till you know how many IU's of vitamin D maintains a true blood level of at least 50 ng/ml.
Now I'm curious if Oprah will follow up with why the vitamin D cofactors are also needed: vitamin K, boron, magnesium, zinc, tiny amount of vitamin A. See www.vitamindcouncil.org for more information.