Immaturity, pregnancy, environmental changes, digestive upsets, sickness or illness are common stages that may result in your cat becoming deficient in key nutritional elements. Sick or injured cats that may be too weak to eat a normal diet may require supplements such as Nutrigel to restore their strength and bodily functions to the norm. Sudden change in diet can also result in dry, flaking skin or hair loss and often an omega supplement such as Megaderm can be mixed into the animal’s food to restore the damage.