MAXI CAL is a high-calcium formula (600mg) with 100iu of Vitamin D, which works with Calcium.

Calcium is the most abundant mineral in the human body, making up about 2 percent of total weight – typically 27 to 32 ounces in adult woman and 35 to 45 ounces in males. About 99 percent of this calcium is stored in the bones and teeth, and the remaining 1 percent circulates in the blood and is found in muscles, nerves, and other soft tissues.