Hypervitaminosis D
Vitamin D toxicityHypervitaminosis D is a condition that occurs after taking very high doses of vitamin D.
Vitamin D
Vitamin D is a fat-soluble vitamin. Fat-soluble vitamins are stored in the body's fatty tissue and liver.
Read Article Now Book Mark ArticleCauses
The cause is excess intake of vitamin D. The doses need to be very high, far above what most health care providers normally prescribe.
There has been a lot of confusion about vitamin D supplementation. The recommended daily allowance (RDA) for vitamin D is between 400 and 800 IU/day, according to age and pregnancy status. Higher doses may be needed for some people, such as those with vitamin D deficiency, hypoparathyroidism, and other conditions. However, most people do not need more than 2,000 IU of vitamin D a day.
For most people, vitamin D toxicity only occurs with vitamin D doses above 10,000 IU per day.
Symptoms
An excess of vitamin D can cause an abnormally high level of calcium in the blood (hypercalcemia). This can severely damage the kidneys, soft tissues, and bones over time.
Hypercalcemia
Hypercalcemia means you have too much calcium in your blood.
Read Article Now Book Mark ArticleThe symptoms include:
- Constipation
Constipation
Constipation in infants and children means they have hard stools or have problems passing stools. A child may have pain while passing stools or may ...
Read Article Now Book Mark Article - Decreased appetite (anorexia)
Decreased appetite
A decreased appetite is when your desire to eat is reduced. The medical term for a loss of appetite is anorexia.
Read Article Now Book Mark Article - Dehydration
Dehydration
Dehydration occurs when your body does not have as much water and fluids as it needs. Dehydration can be mild, moderate, or severe, based on how much...
Read Article Now Book Mark Article - Fatigue and confusion
Fatigue
Fatigue is a feeling of weariness, tiredness, or lack of energy.
Read Article Now Book Mark Article - Frequent urination
- Irritability
- Muscle weakness
Muscle weakness
Weakness is reduced strength in one or more muscles.
Read Article Now Book Mark Article - Vomiting
Vomiting
Nausea is feeling an urge to vomit. It is often called "being sick to your stomach. "Vomiting or throwing-up forces the contents of the stomach up t...
Read Article Now Book Mark Article - Excessive thirst (polydipsia)
Polydipsia
Excessive thirst is an abnormal feeling of always needing to drink fluids.
Read Article Now Book Mark Article - High blood pressure
High blood pressure
Blood pressure is a measurement of the force exerted against the walls of your arteries as your heart pumps blood to your body. Hypertension is the ...
Read Article Now Book Mark Article - Passing large amounts of urine (polyuria)
Polyuria
Excessive amount of urination means that your body makes larger than normal amounts of urine each day.
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Exams and Tests
Your provider will examine you and ask about your symptoms.
Tests that may be ordered include:
- Calcium level in the blood
Calcium level in the blood
Hypercalcemia means you have too much calcium in your blood.
Read Article Now Book Mark Article - Calcium level in the urine
- 25-hydroxy vitamin D level
- 1,25-dihydroxy vitamin D level
- Serum phosphorus level
Serum phosphorus level
The phosphorus blood test measures the amount of phosphate in the blood.
Read Article Now Book Mark Article - X-ray of the bone
X-ray of the bone
A bone x-ray is an imaging test to look at the bones.
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Treatment
Your provider will likely tell you to stop taking vitamin D. In severe cases, other treatment may be needed.
Outlook (Prognosis)
Recovery is expected, but permanent kidney damage can occur.
Possible Complications
Health problems that can result from taking too much vitamin D over a long time include:
- Dehydration
- Hypercalcemia
- Kidney damage
- Kidney stones
Kidney stones
A kidney stone is a solid mass made up of tiny crystals. One or more stones can be in the kidney or ureter at the same time.
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When to Contact a Medical Professional
Contact your provider if:
- You or your child shows symptoms of hypervitaminosis D and has been taking more vitamin D than the RDA
- You or your child shows symptoms and has been taking a prescription or over-the-counter form of vitamin D
Prevention
To prevent this condition, pay careful attention to the correct vitamin D dose. Use vitamin D supplements from reliable licensed sources.
Many combination vitamin supplements contain vitamin D, so check the labels of all the supplements you are taking for vitamin D content.
References
Bringhurst FR, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Auchus, RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology. 14th ed. Philadelphia, PA: Elsevier; 2020:chap 29.
Greenbaum LA. Vitamin D deficiency (rickets) and excess. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 64.
National Institutes of Health Office of Dietary Supplements website. Vitamin D fact sheet for health professionals. ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/. Updated September 18, 2023. Accessed January 19, 2024.
Review Date: 10/29/2023
Reviewed By: Sandeep K. Dhaliwal, MD, board-certified in Diabetes, Endocrinology, and Metabolism, Springfield, VA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.