Vitamin D is important for healthy bones and teeth and a lack of the vitamin has also been linked by some studies to high rates of multiple sclerosis in Scotland.
Overuse of vitamin D, a substance that promotes the growth of bone and teeth in children, can be particularly toxic, as can overuse of the mineral iron by older adults.
She resented it, and it always seemed to set her teeth on edge though if she'd heard it once, she'd heard it a hundred times, so often in fact that her daughter, just learning to talk, had eagerly enlisted in the interrogation.