Vitamin D Toxicity (Hypervitaminosis D)

Vitamin D toxicity happens when you have too much vitamin D in your body. This condition is also called hypervitaminosis D. It almost always results from taking very high doses of vitamin D supplements over time.

Your body needs vitamin D to absorb calcium and maintain strong bones. But too much vitamin D causes your intestines to absorb excess calcium from food. It also triggers your bones to release stored calcium into your bloodstream. This leads to hypercalcemia, which means dangerously high calcium levels in your blood.

Vitamin D toxicity is rare because your body tightly regulates vitamin D from sun exposure and food. You cannot get toxic levels from sunlight alone. The condition typically requires taking 10,000 IU or more daily for several months. Standard doses range from 600 to 2,000 IU per day for most adults.

• Nausea and vomiting
• Loss of appetite and weight loss
• Excessive thirst and frequent urination
• Constipation
• Weakness and fatigue
• Confusion or disorientation
• Kidney stones
• High blood pressure
• Bone pain
• Irregular heartbeat

Some people have no symptoms early on. Blood testing can catch elevated calcium levels before serious complications develop. Symptoms often appear gradually as calcium builds up in your blood and tissues.

Vitamin D toxicity comes from taking excessive amounts of vitamin D supplements. This typically means doses above 10,000 IU per day for months. Prescription vitamin D medications at very high doses can also cause toxicity. Some people take megadoses thinking more is better for bone health or immunity. Others accidentally take too much due to confusing dosing instructions or taking multiple supplements containing vitamin D.

Certain health conditions increase your risk. People with granulomatous diseases like sarcoidosis or tuberculosis produce excess active vitamin D in their tissues. Kidney disease makes it harder to clear vitamin D from your body. Older adults and those with malabsorption conditions may take higher doses and accidentally overdo it. Children are especially vulnerable to vitamin D toxicity from accidental overdose.

Doctors diagnose vitamin D toxicity through blood tests that measure calcium levels. Elevated blood calcium is the hallmark sign of this condition. Your doctor will also review your supplement history and current medications. Rite Aid offers blood testing that includes calcium monitoring, making it easy to check your levels regularly if you take vitamin D supplements.

Additional tests may include vitamin D levels, kidney function markers, and urine calcium. Your doctor looks for calcium levels above 10.5 mg/dL in adults. Very high vitamin D levels above 150 ng/mL combined with elevated calcium confirm the diagnosis. Early detection through routine blood work helps prevent serious complications like kidney damage or heart problems.

• Stop taking all vitamin D supplements immediately
• Avoid calcium supplements and calcium-rich foods temporarily
• Increase fluid intake to help flush calcium through your kidneys
• Use corticosteroids in severe cases to reduce calcium absorption
• Take bisphosphonates to prevent bone calcium release if needed
• Get intravenous fluids for severe hypercalcemia requiring hospitalization
• Monitor calcium levels regularly through blood tests during recovery
• Work with your doctor to determine safe vitamin D doses moving forward
• Treat any underlying conditions that affect vitamin D metabolism

Most people recover fully within weeks to months after stopping supplements. Your calcium levels should return to normal gradually. See your doctor immediately if you have severe symptoms like confusion, extreme weakness, or irregular heartbeat.