There is that store in City Center, opposite and up a bit from Home Centre. Can't remember it's name,  maybe GSM? they have some herbal medicines like Milk Thistle and vitamins, some packets of fibre and bran type things but really it's more for bodybuilders I think, they have loads of those powder drinks and stuff. depends what you are looking for. MegaMart has lots of health foods but they are expensive. Hope this is of some help, jj