well. sure.
Are multivitamins good for you?
Sure, but only if you aren't getting the recommended daily allowance of vitamins through your diet. This should probably apply to vegans more than anyone else.
If you are eating a balanced diet using fresh food, it is extremely unlikely that you will need to do pills. Taking low doses of vitamins probably won't hurt though, and you will be benefiting the shareholders of the drug companies peddling the pills.
If you are taking regular vitamin supplements, or thinking about it, ask your doctor before doing so. And by the way, 100 grams of spinach has healthy amounts of vitamins A, C, E, K, several B vitamins, and essential minerals including iron and calcium. So ditch the vitamins and eat your spinach. Or blueberries.