Corn Syrup
The demand of corn syrup is pretty high because it is used in almost everything. Having a food product, or drink, without corn syrup basically means fresh grown fruits and vegetables and water. In an episode of Supernatural, you see the leader of the Leviathans, supernatural beasts who feed on humans, has purchased SucroCorp., a company that produces corn syrup. What they did was add some things to the corn syrup, literally making humans taste better. It will also dumb them down and boost their appetite so they will fluff themselves up. Adding this ingredient to something so commonly used like corn syrup is a genius idea. They affect so many foods that everyone eats, so it affects tons of people, increasing the Leviathan’s food supply. At about 1:09 to about 2:21, there is an interview with Dick, the leader of the Leviathans, about the purchase of SucroCorp. There is also a slip up about making the humans taste better with the new corn syrup.
By supplying corn syrup with this ingredient, the ingredient infects tons of people. It broadens their “inventory” of food from special picked, and not so delicious, people to almost every human on the planet. By putting the ingredient in such a widely use product, it spreads quickly. The supply of the corn syrup works hand in hand with the demand of food people like. Without the people knowing that the corn syrup is bad for them, they will continue to buy the food they like. The ingredient does cheat a little because it makes the person infected gain a bigger appetite. From about 20:44 to about 22:40, you see the effect the ingredient has on people. The cop is a really enjoyable part. With the ingredient making infected people basically vegetables that can still move and makes them have a bigger appetite, it will sky rocket demand which will sky rocket the supply.
Another version of supply would be humans. Vampires, werewolves, and other things will die when they eat anything with this corn syrup, including eating and biting humans. Doing this will decrease the rate of decrease of supply. That way, Leviathans will be able to feed