Vitamin D toxicity

Condition of excessive vitamin D levels in the body

Overview

Vitamin D toxicity, also known as hypervitaminosis D, is a rare but potentially serious condition that occurs when there is an excessive accumulation of vitamin D in the body. This condition can lead to hypercalcemia, which is an elevated level of calcium in the blood, and can cause various health issues.

Causes

Vitamin D toxicity is usually caused by excessive intake of vitamin D supplements rather than dietary intake or sun exposure. The body regulates the amount of vitamin D produced from sunlight, and it is unlikely to reach toxic levels through diet alone. However, high doses of vitamin D supplements can lead to toxicity.

Symptoms

The symptoms of vitamin D toxicity are primarily related to hypercalcemia and may include:

• Nausea and vomiting
• Weakness
• Frequent urination
• Kidney stones
• Bone pain
• Confusion
• Fatigue

Pathophysiology

Chemical structure of cholecalciferol, a form of vitamin D

Vitamin D is a fat-soluble vitamin that is essential for maintaining bone health and calcium homeostasis. It is converted in the liver to 25-hydroxyvitamin D, and then in the kidneys to its active form, calcitriol. Excessive levels of vitamin D increase calcium absorption from the gut, leading to hypercalcemia.

Diagnosis

Diagnosis of vitamin D toxicity is based on clinical symptoms, history of excessive vitamin D intake, and laboratory tests showing elevated levels of 25-hydroxyvitamin D and calcium in the blood.

Treatment

The primary treatment for vitamin D toxicity is to stop taking vitamin D supplements and reduce calcium intake. In severe cases, hospitalization may be required to manage hypercalcemia with intravenous fluids and medications such as bisphosphonates or corticosteroids.

Prevention

To prevent vitamin D toxicity, it is important to adhere to recommended dietary allowances and avoid excessive supplementation. Regular monitoring of blood levels of vitamin D and calcium is advised for individuals taking high doses of vitamin D.

Related pages

• Vitamin D
• Hypercalcemia
• Kidney stones