You can choose: Sell something people want, or sell something that people need.
Sell something that keeps people healthy, or sell something that takes away the pain.
Sell vitamins, or sell aspirins.
Its easiest to sell things that take away pain.
Pain creates need. Need creates pressure. Customers will dig into their pockets when under pressure.
Look for pressing problems, solve them, sell a solution that takes away pain.
Leave vitamins to people who want to save the world.