Do you need to take iron supplements if you taking ppis for gerd?

No: Although there is a lot of talk about iron absorption while on PPIs on the Internet, the practical aspect of it is that the effect of PPI's on this is very minimal. There is no reason to take extra iron supplements. If you need to be on PPI's for years, it might be reasonable to check a blood count every year or so. Otherwise, you are unlikely to have problems. Good luck.