The 8th annual Natural Products Asia Show will be held on 28 August 2010 (open to traders only on 26th, 27th). It is an annual expo in Hong Kong for natural products including spa, vitamins, organic food, health products, and health food including gluten free products!
I've never been, but this show is on in HK every year around the same time.
Definitely check it out if you are free that day!
See here for my shopping from the show.