Potassium sorbate is naturally found in some fruits (like the berries of mountain ash) and the ingredient is produced as a “nature identical” chemical (chemically equivalent to the molecule found in nature). It is used in small amounts as a preservative to prevent spoilage from bad bacterias, molds, etc, which is incredibly important in keeping your product safe!
We use the smallest amount of potassium sorbate needed. Without a preservative, all such vitamins would spoil within days. We try to bring the purest products to our customers, while still making sure that they are always safe.