FYI: husband took 50, 000IU orally once a week X's 2 and developed kidney stones. coincidence? was reassurred there was no association, though I remember problems with calcium metabolism (and thus precipitation of same resulting in stones) associated with Vit D therapy. Perhaps if one stays well hydrated? again, may have been a coincidence, though husband had never had kidney stones before and has not suffered with them since. He now takes 2000 IU/day.
http://www.parkhurstexchange.com/nephrology/2010-01-09
"...Vitamin D intoxication by increasing calcium absorption is known to cause and increase risk of calcium based kidney stones. It's unclear, however, to what extent physiologic doses of vitamin D alone increases this risk, as it's often given along with calcium to preserve bone health..."