Hypercalcemia is a serious electrolyte abnormality caused by excessive exposure to or ingestion of vitamin D. Symptoms of vitamin D toxicosis, which can affect multiple organ functions, usually occur within 24 to 72 hours of ingestion and include anorexia, vomiting, diarrhea, polyuria, polydipsia, depression and weakness. Initially, clinical signs may be vague and nonspecific.
Excessive amounts of vitamin D in an animal’s bloodstream can increase calcium and phosphorus levels within 12 to 24 hours after initial exposure and persist for days and weeks. As calcium and phosphorus levels rise, they can affect the kidneys as well as the heart, gastrointestinal tract and the central nervous system. Acute renal failure, coma and death can occur in severe or untreated cases.