With Trace Minerals and Vitamin D NOW Cal-Mag Caps contains the minerals that are essential for bone health.* In addition to Calcium and Magnesium, Cal-Mag Caps provide chelated, highly absorbable forms of Zinc, Copper and Manganese, three trace minerals known to support healthy bone metabolism.* Vitamin D has also been included to support Calcium metabolism.* Natural color variation may occur in this product. L-OptiZinc is a registered trademark of InterHealth Nutraceuticals Inc.