I've had it happen twice, with two different dosages. First time was at a higher dosage than 1000 and I think it happened sooner.
I'm just calling it out here, because sometimes you get lucky and someone else had the same issue and has the answer and will resolve the mystery.
I'm not saying Vit D is bad, I'm just curious if others have had difficulties with it.
My doctors opinion on it is everyone is low on Vit D, so just take some.
A web search brings up - https://www.reddit.com/r/Biohackers/comments/1ia6yyb/update_...
tl;dr - some Vit D supplements are based on lanolin. if you're sensitive to it, you may switch to a supplement that doesn't use lanolin. also one response talks about taking a multi-Vitamin B supplement for anger issues with Vit.D