Traditionally associated with milk and excessive sodium bicarbonate containing antacids it is hypercalcaemia caused by high inorganic calcium intake (2g or more in adults) which now most commonly occurs with calcium carbonate preparations for phosphate binding or osteoporosis prophylaxis. Patients tend to develop a metabolic alkalosis and renal failure.
Treatment is by withdrawal of the calcium (and cause of gastric alkaline load) and correction of volume depletion. Bisphosphonates are not really indicated.
Some sources doubt its existence (due to technicalities due to other predisposing conditions).