The smaller Reno Store on Plumb Lane has a smaller supplements department (there is less wall space, at least one fewer aisle, and the aisles are shorter) but perhaps it is proportionate with the downsizing of other parts of the store too.
That is a super high margin category for them (until they go do inventory and see how much was stolen). They have cut SKUs significantly in that category over the years. I find their supplement category to be largely useless. The couple times I tried to go buy something there lately in that category, it was either not carried or was out of stock. Recently even a mouthwash I had been buying and knew they had, they didn't have anymore. I had to go buy at Natural Grocers.
However in observing transactions at Sprouts I do see purchases occurring from that department (usually just single item purchases) and the purchases tend to be fairly high dollar. While that department may appear to be a waste of space my guess is it actually carries itself due to the high mark up of the items involved.
Regular supplement users order online due to the prices being so much lower. Places like Sprouts, Natural Grocers, Vitamin Shop, etc. are only for immediate need.