Calcium is an essential mineral required for the formation of skeletal tissues. In shrimp, the vast majority of body calcium is found in the exoskeleton. Calcium is also essential for blood clotting, activation of enzymes, muscle contraction and cell permeability, and is believed to be essential for the absorption of Vitamin B₁₂ (Akiyama et al., 1992).

The shrimp culture environment usually has a high concentration of calcium which is directly absorbed by shrimp. Therefore, calcium is not considered a dietary essential. However, the calcium level in the feed needs to be monitored to maintain a calcium:phosphorous ratio of 1:1 to 1.5:1. Calcium should not exceed 2.3% in the feed and should be minimized (Akiyama et al., 1992).