Decent brandable. Probably worth high XXX to low X,XXX to end user. Reseller XX to low XXX.
Tough, saturated market with more and more regulation every year. If developed, I would stay away from just a typical ecom site.
Maybe something more unique and hand coded that had the user fill out some kind of questionnaire (diet, activity, age, sex, etc.) and then created a free monthly vitamin and supplement plan.