I’ve written about Vitamin D before: http://draimee.org/vitamin-d-ms-and-pregnancy/
It’s in the news again: http://www.acog.org/from_home/publications/press_releases/nr06-20-11-2.cfm
The American College of ObGyn has recently submitted a statement that routine screening for Vitamin D is not recommended. I pasted the link above. The Harvard newsletter (December 2010) recommends 1,000-2,000 IU of vitamin D per day, while the Vitamin D Council recommends up to 5,000 IU in pregnancy while the the Institute of Medicine Food and Nutrition Board (FNB) recommends 600 IU daily. Most prenatals contain 400 IU. I don’t understand why there is such a discrepancy between the recommendations but I do know why vitamin D is very important in pregnancy: because it plays a very important role in fetal health.
Vitamin D deficiency has been found to be a risk factor in autism, multiple sclerosis, and fetal skeletal abnormalities.
I screen for vitamin D deficiency because I do think there is enough evidence to support routine screening despite what the American College of ObGyn’s press release states. But read the data yourself, talk to you doctor, and see what’s right for you.