Researchers were surprised to find so few positive effects from the most common vitamin and mineral supplements.
These are used in everything from mobile phones to washing machines.
Bazooke Rhadebe's call for the right to say no to mining companies has echoes all over South Africa.
Nutritional deficiencies can lead to the development of psychiatric disorders and cognitive decline.
A huge drop in exports may pile pressure on leader Kim Jong Un.
Bridgmanite is buried deep in the planet's lower mantle, making it nearly impossible to study.