I tested very low for vitamin D and so my ob/gyn put me on a very high dose for the next 8 weeks (I found out when I was 7 weeks pregnant). After 8 weeks, I'll take 1000mg every day until the end of my pregnancy.
I don't think there's conclusive evidence that low vitamin D is problematic during pregnancy but some recent studies suggest that it may be linked to respiratory problems.
Good luck!
if all else fails....google!!!
im not sure what vitamin D is for but if i were in your shoes i would be googling the heck out of it
good luck