People who are on the lower end of normal or just below normal may benefit from taking 5,000 to 10,000 IU of vitamin D, ...

Research shows that one billion people around the world are vitamin D deficient—here's how to know if you're potentially one ...

Plant cells have several structures not found in other eukaryotes. In particular, organelles called chloroplasts allow plants to capture the energy of the Sun in energy-rich molecules; cell walls ...