What Rainbow's end lacks in stock, they make up for in service!
RE is a smallish health food and product (mostly product) store on Sahara, just east of the strip. Nice for those in central (like me) who don't want to truck it all the way out to GV or summerlin to Whole Foods.
In terms of the store, the food selection is pretty sparse; there is a small refrigerated section of organic, raw dairy and juice items, flax seed oil, the usual. The reason you'd go here though is for the teas, supplements, essential oils etc. The staff are VERY helpful and knowledgeable...and have advised me on different items I've considered or bought. Prices are fair considering the general lack of health stores in this part of town.
They do have a kitchen/restaurant area on the side, but I haven't tried it yet.