I know that lots of food, such as bread and cereal, has added vitamins. But I didn't realise just how important this is for developing countries.
This year the World Food Prize has been awarded to four scientists who developed a new sweet potato fortified with vitamin A. They used traditional plant breeding to make a variety that contains higher levels of the vitamin and can also survive in dry soils.
Millions of people are affected by vitamin A deficiency, which can cause blindness. I hope innovations in farming such as this one can help.