Polycernol seems natural and all but couldnt I just change my diet and take a regular vitamin for prostate health?

The ingredients are pretty good. It's a lot easier to take a pill than to change your diet to include these ingredients. Supplements are a perfectly good way to help us get the nutrition we need. Check out this review for Polycernol to see what they say about it.
The reviews are not very good, so you may want to keep looking for a product that has a higher consumer rating.