Alright first things first if you aren't taking a multivitamin START NOW!
Here's a breakdown of what you want in your multivitamin
Biotin: 30 mcg
Folic Acid: 400 mcg
Pantothenic Acid: 5mg
Vitamin A: 2500 IU
Vitamin B6: 2mg
Magnesium: 320mg (woman) 420mg (men)
Vitamin B12: 30mcg
Vitamin C: 400mg
Vitamin D: 2000IU
Vitamin E: 200IU
Vitamin K: 10-20mcg
EPA and DHA Omega-3 fatty acids: 1g
So take a look at your multivitamin and see how it shapes up. Like I have said before, I take One a Days for woman, it holds up pretty well against these numbers. But I add a calcium supplement and take fish oil for the Omega-3 fatty acids.