Vitamins / Minerals are essential for optimum health for all living species. Requirements differ from one species to the next, but they all need adequate amounts of each mineral for healthy bodily functions. Mineral deficiencies can lead to disease and so can mineral excesses. So getting the correct amount in the right ratios is the key to optimum health. Most natural diets will provide these minerals in appropriate balances, but with commercially prepared diets, this can cause imbalances.