> Vitamin A deficiency in developing countries causes hundreds of thousands of children to go blind each year. It also reduces the body’s ability to fight infec

> Vitamin A deficiency in developing countries causes hundreds of thousands of children to go blind each year. It also reduces the body’s ability to fight infection, which raises the fatality rates in poor countries from infectious diseases like measles. Iron deficiency is so serious and widespread that in Uganda, for example, more than 40 percent of young children have stunted growth and 73 percent are anemic. I take your point that calories aren't trivial for a developing world staple but it's difficult to see it counter-balancing that situation.