Well, you don't necessarily *need* them. Most sites recommend taking them just to make sure you aren't deficient in any vitamin, through poor diet or whatever.
Providing you don't take more than one tablet a day (if it's a one-a-day tablet), it won't do you any harm - most vitamins you'd have to take 5x/10x the daily recommended dose before it could become harmful.
Do consider those other supplements I mention - if you're serious about getting bigger, you need to look after your joints to help prevent injury.
I notice you say you're lifting daily, what does your weekly routine look like? Lifting weights every day isn't recommended, as you don't give you body enough time to recover - remember that your muscles grow when you're resting, NOT in the gym!