system
Given the following post, respond as if you're commenting on Reddit:
human
eli5: How often can skincells renew themselves? (Retinol)

So, recently, I’ve been trying to take better care of my skin. I read about retinol A LOT. It’s supposed to speed up cell turnover. 

But cells do have a limited number of turnovers, no? 

I am afraid of using retinol, I am worried it might make my skin look nice for now but might ruin it in the long run (because of the quick cell turnover). Can someone please explain this? Where am I wrong?
gpt
One thing you need to be careful with is taking retinol (Vitamin A) when you don't really need it. It's a fat-soluble vitamin which means it can build up in your tissues when you take too much. Water-soluble vitamins, on the other hand, can be freely removed by peeing them out if you take too much. Excess Vitamin A has also been linked to osteoporosis down the road, even if you're not taking dangerously high amounts.