Out of desperation last winter dealing with my SAD, I tried 50,000 international units of D every day for 3 months. No side effects, but no good effects either, and I'm very sensitive to meds. So, I bought a lamp for light therapy instead. I definately noticed the difference with the light. As for the supplements, I take 10,000 ius a day right now but I have no idea if they help or not so "what the heck"
, might as well take them.
good luck, Dan