Question: what are the side effects of too much calcium in the blood?
Answer: Kidneys. Excess calcium makes your kidneys work harder to filter it. ... 
Digestive system. Hypercalcemia can cause stomach upset, nausea, vomiting and constipation.
Bones and muscles. In most cases, the excess calcium in your blood was leached from your bones, which weakens them. ... 
Brain. ... 
Heart.