A: It is fine to take a regular, over-the-counter multivitamin for a short time until you get your prescription refilled. This would not be advisable for long periods of time because prenatal vitamins have different amounts of certain vitamins and minerals that are specially formulated for pregnancy. For example, there is more iron in a prenatal vitamin than in a regular multivitamin. And, most prescription prenatals have DHA, a fatty acid thought to be important in fetal eye and brain growth, whereas many over the counter formulations do not. You can also ask your practitioner to give you some samples to help you temporarily.