https://www.harvestplus.org/what-we-do/nutrition
Over two billion people around the world suffer from "hidden hunger" or micronutrient deficiencies.
They do not get enough micronutrients from the foods they eat to lead healthy, productive lives. Micronutrients are vitamins and minerals such as vitamin A, zinc, and iron. Although they are only required by the body in very small amounts, they are essential to good health and preventing illness.
Many of the symptoms of micronutrient deficiencies cannot be seen — such as lower IQ, lower resistance to disease, and fatigue. This is why this form of malnutrition is known as "hidden hunger".
The diets of the poor in developing countries usually consist of very high amounts of staple foods (maize, wheat, rice, etc.) but few micronutrient-rich foods such as fruits, vegetables, and animal and fish products.
Biofortified crops, which have been bred to have higher amounts of micronutrients, can help provide these essential vitamins and minerals. They are effective in reducing hidden hunger and are an integral component of food-based approaches to improve nutrition and food security, including dietary diversification, supplementation, and commercial fortification, among others.