It can be produced from a non-animal source. If it is found in a parve food, then it contains no trace of dairy. This is a guesstimate, based on my opinion of how likely it is that the manufacturing process will start with a dairy product. As I stated before, none of these additives will contain sufficient lactose to be noticeable by any but the most sensitive individuals. This will be controversial to some people, but my reading on the subject leads me to believe that there is as great a variation in allergy sensitivities as there is in intolerance sensitivities.
Many people have a much milder hypersensitivity rather than a true allergy.
If you don't want to take any chances, and understandably so, then simply avoid foods that contain any of these unless they are parve, or unless you have checked with the manufacturer. Lactic Acid A widely used acid, flavouring, preservative, and synergist for antioxidants which occurs as a by-product of lactic fermentation of carbohydrates in milk, meat and beers. Prepared by fermenting sugar or by chemical synthesis. Produced commercially by the fermentation of whey, cornstarch, potatoes, and molasses. Kosher, pareve without supervision.