Dietary Supplement. Nervous System Support. Supports Energy Production. Critical for Enzyme Function*. Vegetarian Formula Magnesium Citrate is produced from the synthesis of Magnesium Carbonate and Citric Acid and is a readily bioavailable source of this key material. It plays key roles in the activation of amino acids for protein biosynthesis and is highly concentrated in intracellular fluid and bone.* Contains no sugar, salt, starch, yeast, wheat, gluten, corn, soy, milk or preservatives. Quality GMP Assured.