The Canadian Food Inspection Agency restricts the use of "natural" to foods that have not been significantly altered by processing and gives examples of processes that do or do not significantly alter food.  This includes two specific additional requirements:
*A natural food or ingredient of a food is not expected to contain, or ever to have contained, an added vitamin, mineral nutrient, artificial flavoring agent or food additive.
*A natural food or ingredient of a food does not have any constituent or fraction thereof removed or significantly changed, except the removal of water.