Lifestream natural magnesium powder 150g lifestream natural magnesium is a naturally derived marine source extracted from seawater which naturally contains magnesium salts it is manufactured by filtration blending and heat drying without the need for adding preservatives or chemical products to form a highly bio available and concentrated dose of elemental magnesiumdespite the essential nature of magnesium there is no specific food that provides a high amount of magnesium good sources of