Hypervitaminosis D

Vitamin D toxicity, also called hypervitaminosis D, is a rare but potentially serious condition that occurs when excessive amounts of vitamin D in human body. It is usually the result of taking high-dose vitamin D supplements. Hypervitaminosis D is characterized by a considerable increase in circulating 25(OH)D levels up to a level of approximately 160–500 ng ml−1 plasma.

It is usually due to taking more than the recommended daily value of vitamin D. Some prescription medications used to treat high blood pressure (thiazide diuretics) and heart diseases (digoxin) can cause an increase in vitamin D in the blood.

Hypervitaminosis D and its clinical manifestation, severe hypercalcemia, are related to excessive long-term intake of vitamin D, malfunctions of the vitamin D metabolic pathway, or the existence of coincident disease that produces the active vitamin D metabolite locally.

The main consequence of vitamin D toxicity is a buildup of calcium in human blood (hypercalcemia), which can cause nausea and vomiting, weakness, and frequent urination.

The most often noted clinical symptoms of Hypervitaminosis D include: confusion, apathy, recurrent vomiting, abdominal pain, polyuria, polydipsia, and dehydration. Vitamin D toxicity might progress to bone pain and kidney problems, such as the formation of calcium stones.

Long-term high-dose D supplement intake may result in adverse health effects, increase in mortality, greater risk of pancreatic cancer, cardiovascular events, and increased falls and fractures in the elderly.
Hypervitaminosis D