Hypervitaminosis D is a rare but potentially serious condition. It occurs when you take in too much vitamin D. It is usually caused by taking high-dose vitamin D supplements. Too much vitamin D can lead to abnormally high levels of calcium in the blood. It can affect bones, tissues and other organs. If left untreated, it can lead to high blood pressure, bone loss, and kidney damage.

Causes of hypervitaminosis D

You probably don’t get too much vitamin D from the foods you eat or from exposure to the sun. However, cases have been reported due to the use of tanning beds. There has been an increase in cases of hypervitaminosis D in general in recent years. It is usually due to vitamin D intake above the recommended daily value. If you take a multivitamin, check how much vitamin D it contains. You may not need to take extra calcium and vitamin D if your multivitamin provides you with enough vitamin D.

Some prescription drugs used to treat high blood pressure (thiazide diuretics) and heart disease can cause an increase in vitamin D in the blood.

Estrogen therapy, prolonged use of antacids, or anti-tuberculosis medication can also cause high vitamin D levels.
The recommended dietary allowance of vitamin D for most adults is 600 international units per day (IU). Doctors may prescribe higher doses to treat medical conditions such as vitamin D deficiency, diabetes, and cardiovascular disease, for a short time. Using high-dose vitamin D supplements daily for several months is toxic.

You are more likely to develop hypervitaminosis D if you take vitamin D supplements and have other existing health conditions, such as:

– kidney disease
– liver disease
– tuberculosis
– hyperparathyroidism
– sarcoidosis
– histoplasmosis

Symptoms of Hypervitaminosis D

Excessive amounts of vitamin D in the body can cause calcium levels in the blood to rise. This can lead to a condition called hypercalcemia (too much calcium in the blood). Symptoms include:

– fatigue
– loss of appetite
– weightloss
– excessive thirst
– excessive urination
– dehydration
– constipation
– irritability, nervousness
– ringing in the ear (tinnitus)
– muscular weakness
– nausea, vomiting
– dizziness
– confusion, disorientation
– high blood pressure
– cardiac arrhythmias

Long-term complications of untreated hypervitaminosis D include:

– kidney stones
– kidney damage
– renal failure
– excessive bone loss
– calcification (hardening) of the arteries and soft tissues.

Also, increased blood calcium can cause abnormal heart rhythms.


Your doctor will review your medical history and may ask you about any prescription or over-the-counter medications and supplements you take.
They may also perform a physical exam and ask you about your symptoms. If your doctor suspects you have hypervitaminosis D, they may order tests, including:

– blood tests to check vitamin D, calcium and phosphorus levels (to determine if the kidneys are damaged)
– urine tests to check for excessive amounts of calcium in the urine
– X-rays of the bones to determine if there is significant bone loss.


Your doctor will likely advise you to immediately stop taking vitamin D supplements. They may also recommend that you temporarily reduce the amount of calcium in your diet. In some cases, corticosteroids or bisphosphonates can suppress the release of calcium from your bones. Your doctor will frequently monitor your vitamin D levels until they return to normal.


Stopping or reducing high-dose vitamin D supplements can prevent hypervitaminosis D. The tolerable upper limit, or maximum daily intake of vitamin D that is not likely to cause health risks health, has been set at 4,000 IU per day. Adverse effects have been seen in people taking less than 10,000 IU per day for a prolonged period.

Your doctor may also recommend that you reduce the amount of calcium in your diet. Careful monitoring is necessary until your vitamin D levels return to normal.

To ingest vitamin D naturally, you can eat foods that are rich in it, including:

– Cod liver oil
– fatty fish, such as salmon and tuna
– beef liver
– cheese
– the egg yolk
– certain mushrooms

Moderate exposure to sunlight is another source of natural vitamin D. Fifteen minutes or less with your extremities exposed to direct sunlight, before putting on sunscreen, is a great way to boost your vitamin D levels naturally.


Laurent, MR, Gielen, E., Pauwels, S., Vandershueren, D., Bouillon, R. (2017, January 17). Hypervitaminosis D associated with tanning bed use: A case report. Annals of Internal Medicine, 166(2), 155-156

Vitamin D. (2014, November 10)

Vitamin D. (2011, June 24)