My vitamin d level is 29, should i take a supplement and how much per day?

Verify normal range: First you have to see what is the normal range in the test done by yourm doctor, if you a regimen of high dose vitamin d will be indicated, if level is normal daily recommended intake base on you diary intake will be appropriate.

Probably not needed: The institute of medicine recently did a review of vitamin d needs. They concluded that we probably take more than we need. It is hard to tell from your number just what form of vit d was measured, and what the units are. If you are referring to vit d oh, measured in ng/ml, a level of 20 ng/ml is thought to be adequate.