NATURAL FACTORS - Magnesium Citrate - 180 Capsule(s) - NPN: 80005226 -- Magnesium is required for the formation of bones and teeth, and for nerve and muscle function. It is involved in numerous enzyme reactions that keep the body working properly. It regulates growth and development, and supports immune function and temperature regulation. Shaky hands, tension headaches, nervousness, and muscle spasms all respond favourably to magnesium.