Citric acid is organically found in many fruits and is naturally created in the human body. As an ingredient, it is produced by introducing simple carbohydrates from sugar beets to a common, naturally-occurring fungus. The byproduct is citric acid which is used to maintain proper pH levels and improve product flavor. 

CalciuMK+ (for flavor and to maintain pH)
Daily Build (liquid only)
ENERGY (for flavor)
GoYin (helps maintain pH)
GPS Energize (for flavor)
GPS Hydrate (for flavor)
GPS Circulate (for flavor)
GPS Reset (for flavor)
PURE Cafe (helps maintain pH)