I was actually diagnosed as severely deficient during routine blood work. I've been on a prescription 50,000iu dose once a week for I believe about 8 weeks now?
I wouldn't take additional supplements unless your doc has run your levels and declared that you need them. Unlike the natural vitamin D we get from the sunlight that you can't get too much of, too much **synthetic** vitamin D can have adverse affects on your and baby's health.
It can be dangerous to be deficient for many reasons, but just as dangerous to be taking more than you need artificially.