I think you mean 200iu, right? 200mcg is a crazy high dosage of Vitamin D.
According to the National Institutes of Health (NIH), the daily Adequate Intake (AI) for adults is 5 mcg (200 IU) daily for males, female, and pregnant/lactating women under the age of 50. People 50 to 70 years old should get 10 mcg daily (400 IU) daily, and those over 70 should get 15 mcg daily (600 IU).
I personally supplement with 400iu (10mcg) per day. I like to air on the side of caution and use a slightly higher dosage then probably needed. Anything more then that really isn't needed.