The Role of Sorghum in Managing Vitamin A Deficiencies among Certain African Populations

Sorghum is rich in protein, fiber, and vitamin B, but quite poor in vitamin A and certain minerals. Scientists focus on developing sorghum hybrids with higher concentrations of such elements. The aim is to meet the nutritional needs for such elements among the sub-Saharan populations – especially children, to whom sorghum is a staple food.

For more than twenty years, scientists in various research centres⁽¹⁾  have been working on developing sorghum varieties richer in vitamin A and able to absorb a greater amount of minerals like iron and zinc. The aim is to mitigate perceived food deficiencies in the diets of sub-Saharan African populations, especially in mothers and children, to whom sorghum porridge is a staple food and represents an important source of glucides. Vitamin A deficiencies disrupt the immunity system and increase the risk of blindness and death by infection, especially in young children.

First Encouraging Results, in the Labs

Despite being rich in protein, fibres, and vitamin B, sorghum has low levels of vitamin A. It also contains phytic acid, a natural antinutritional compound that prevents the gastrointestinal absorption of minerals such as iron and zinc. For this reason, researchers have been focusing on the development of sorghum hybrids with higher levels of vitamin A and containing a more efficient phytase – an enzyme that can degrade phytic acid. Researchers use biotechnology tools to select relevant genes and include them into the plants’ genome.

Striking the Right Balance

At the same time, researchers have been carrying out trials to see how the various porridge preparations can influence the degradation of phytic acid and the availability of minerals for absorption. They do it by simulating a digestive model in the laboratory, which imitates the human digestive system. The researchers’ objective is to find the optimal point of balance, as increasing the mineral concentration within the intestine seems to indeed reduce the absorption of vitamin A. However, the first results are promising, as the first developed lines of sorghum can provide thirty-two times more vitamin A compared to traditional sorghum varieties, whilst presenting higher levels of zinc and iron. Thus a few meals of porridge made of these new hybrids may at least in theory be sufficient to provide the daily supply of vitamin A to a child between four and eight.

Nevertheless, future trials on humans will be necessary in order to validate these first results that are so encouraging and promising to many African populations.