Nerve and Bone Support Reverse 2:1 Ratio With Zinc and Vitamin D-3 Non-GMO A Dietary Supplement Minerals Family Owned Since 1968 GMP Quality AssuredThis reverse ratio formula is formulated to provide higher levels of Magnesium for those who desire the never, muscle and bone supporting effects of this essential mineral. Zinc and Vitamin D-3 are included in this product for their roles in bone metabolism.