21st Century Magnesium supports protein synthesis and cellular energy. Magnesium is necessary for the metabolism of calcium, vitamin C, phosphorus, sodium, and potassium...all important nutrients for overall human health. Magnesium is also essential for nerve and muscle function, as well as for converting blood sugar to energy. One of the most important minerals in the diet, magnesium is essential for strong muscles and bones, cardiovascular health and nervous system function.