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Hypervitaminosis D

Vitamin D toxicity


Hypervitaminosis D is a condition that occurs after taking very high doses of vitamin D.



The cause is excess intake of Vitamin D. The doses need to be very high, far above what a medical provider would normally prescribe.

There has been a lot of confusion caused by internet articles about Vitamin D supplementation. It is extremely unusual for anybody to need more than 2000 IU of Vitamin D a day.

For most people, Vitamin D toxicity only occurs with Vitamin D doses above 10,000 IU per day.




An excess of vitamin D causes abnormally high levels of calcium in the blood (hypercalcemia). This can severely damage the kidneys, soft tissues, and bones over time.

  • Constipation
  • Decreased appetite (anorexia)
  • Dehydration
  • Fatigue
  • Irritability
  • Muscle weakness
  • Vomiting


Exams and Tests


  • Excess calcium in the blood (hypercalcemia)
  • Excess calcium in the urine (hypercalciuria)
  • Excessive thirst (polydipsia)
  • High blood pressure
  • Passing large amounts of urine (polyuria)

Tests to confirm the diagnosis:

  • 1,25-dihydroxy vitamin D levels
  • 25-hydroxy vitamin D levels
  • Serum calcium
  • Serum phosphorus
  • X-ray of the bone




Stop taking vitamin D. Talk to your health care provider. In severe cases, other treatment may be needed.


Outlook (Prognosis)


Recovery is expected.


Possible Complications


  • Dehydration
  • Hypercalcemia
  • Kidney damage
  • Kidney stones


When to Contact a Medical Professional


Call your health care provider if:

  • You or your child shows symptoms of hypervitaminosis D and has been taking more vitamin D than the recommended daily allowance
  • You or your child shows symptoms and has been taking a prescription form of vitamin D




To prevent this condition, pay careful attention to the correct vitamin D dose.



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        Tests for Hypervitaminosis D


          Review Date: 11/7/2013

          Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

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