Dietary Supplement Formulated for Enhanced Magnesium Absorption BioCitrate Magnesium is a special chelated form of magnesium using citric acid. Minerals bonded with citric acid are specially formulated for people with low stomach acid and are intended to improve mineral bioavailability. Magnesium participates in numerous enzymatic reactions in the body and intended to provide nutritive support for normal, healthy heart, muscle, nerve and circulatory function.