Blackmores Bio Magnesium is a high dose tablet to reduce muscle cramps, tension and stiffness when dietary intake is inadequate. The one-a-day formula also supports heart, bone and nervous system health. Blackmores Bio Magnesium is formulated with a combination of two forms of magnesium plus extra nutrients including vitamins B6, & D. Formulated to assist in the relief of muscular cramps when magnesium levels are low. It uses premium quality ingredients to deliver a high dose (301.5 mg) of magnesium