A new Canadian study concludes if all women of childbearing age, not just those trying to get pregnant or who already are, should take the daily dose to reduce the risk of a wide range of birth defects.

The director of MotherRisk at Toronto's Hospital for Sick Children says one reason all women should take the daily multi-vitamin is that half of all pregancies are unplanned.

Almost all birth defects develop in the first trimester.

It's important women take a pre-natal multi-vitamin, which is different than a regular multi-vitamin.

The former has more folic acid, more iron, and less vitamin A, which at high levels can harm a fetus.