Vitamin D Toxicity - Causes, Symptoms, Diagnosis, Risk Factors, and Management

Introduction

Vitamin D is essential for nerves, muscles, bones, and the immune system. It is a fat-soluble vitamin that can get stored in adipose tissues and the liver. Taking high doses of this vitamin D can cause toxicity in the body as it can cause hypercalcemia or calcium buildup in a person's body. The condition can also lead to kidney problems like calcium stone formation and bone pain. Vitamin D toxicity is potentially caused by overdosing on vitamin D supplements, not by sun exposure or food. It can also lead to an imbalance in bone metabolism along with hypercalcemia and thus causes symptoms of toxicity in the person’s body. In addition, antacids, anti-tuberculosis medicine, estrogen therapy, and isoniazid can also cause hypervitaminosis D in a person. The doctors usually recommend 600 IU of vitamin D in adults for treating the deficiency. Still, the dose can be increased for shorter durations to treat certain conditions like diabetes, severe vitamin D deficiency, and cardiovascular diseases. Regular consumption of vitamin D for a prolonged period can cause toxicity in the body.

What Are the Various Good Sources of Vitamin D?

The sources of vitamin D are:

• Red meat.

• Oily fish.

• Fortified foods such as breakfast cereals and fat spreads.

• Egg yolks.

• Liver.

• Cheese.

What Are the Causes of Vitamin D Toxicity?

Vitamin D supplements are prescribed by the doctor when a person suffers from a deficiency of vitamin D. Excess of vitamin D supplements taken by people mainly causes vitamin D toxicity. However, the food one eats does not have large amounts of vitamin D, so it cannot cause toxicity. Therefore, people consume vitamin D supplements for several months and in much higher doses than the doctor prescribes, which leads to vitamin D toxicity.

What Are the Symptoms of Vitamin D Toxicity?

The symptoms of vitamin D toxicity are as follows:

• Constipation.

• Irritability.

• Dehydration.

• Nausea and vomiting.

• Muscle weakness.

• Kidney stones.

• Pain.

• Confusion.

• Tiredness.

• Loss of appetite

• Pain.

• Excessive thirst with frequent peeing.

• Tinnitus.

• High blood pressure.

What Is the Common Cause of Vitamin D Toxicity in Children?

Vitamin D toxicity or hypervitaminosis D in children mainly occurs during the treatment of rickets. The condition arises from accidental intake of high vitamin D and causes symptoms such as constipation, lethargy, weakness, vomiting, anorexia, loss of appetite, hypotonia, and weakness. It also causes an increase in serum calcium levels in the child's body. Vitamin D toxicity also increases the risk of kidney stones in children. Mostly young children are more at risk of developing hypervitaminosis D.

Which Health Issues Can Lead To Vitamin D Toxicity in a Person?

Vitamin D toxicity in a person can occur due to overconsumption of vitamin D supplements prescribed by the doctor to treat medical conditions such as

• Psoriasis.

• Osteoporosis.

• Renal osteodystrophy or skeletal problems caused by advanced kidney disease.

• Malabsorption or trouble getting essential nutrients from the diet.

The condition can also occur if a person has some underlying conditions and still consumes vitamin D supplements. These medical conditions are as follows:

• Tuberculosis.

• Kidney disease.

• Histoplasmosis.

• Liver disease.

• Sarcoidosis.

• Hyperparathyroidism.

How Is Vitamin D Toxicity Diagnosed?

The doctor can diagnose hypervitaminosis by physically examining a person and asking about the various symptoms. In addition, the doctor may also recommend various lab tests for diagnostic purposes. These tests include

• Calcium levels in urine and blood.

• Vitamin D levels in the blood.

• Phosphate levels in the blood.

• X-rays of the bone to determine if there are any signs of bone loss.

How Is Vitamin D Toxicity Treated?

The doctor treats vitamin D toxicity in the following ways:

• First, the doctor will ask to stop the patient's vitamin D and calcium supplements.

• The doctor also monitors calcium levels during vitamin D toxicity treatment.

• The doctor also manages the amount of calcium the patient consumes through food with a proper diet plan to limit calcium intake.

• If a person suffers from kidney failure, hemodialysis is done to filter out the waste.

• Sometimes, a doctor may need to give intravenous fluid to the patient to treat dehydration caused by vitamin D toxicity.

• In addition, intravenous bisphosphonates are used to treat hypercalcemia, and corticosteroids are given to a person to reduce plasma calcium levels during vitamin D toxicity.

• Corticosteroids or bisphosphonates also help in inhibiting bone resorption during hypervitaminosis D.

• Radiographic diagnosis is not required in case of vitamin D toxicity, but if a person has mental status altered during admission to the healthcare center, a CT (computed tomography) scan of the brain should also be done.

What Is the Prognosis for Vitamin D Toxicity?

The person usually recovers from vitamin D toxicity without significant complications. Some cases may develop hypercalcemia causing acute renal failure in a person. However, vitamin D toxicity rarely causes kidney failure.

What Are the Long-term Complications of Vitamin D Toxicity?

The long-term complications include

• Kidney failure.

• Kidney stone.

• Excess bone loss.

• Kidney damage.

• Hardening of soft tissues and arteries.

• Hypercalcemia.

What Is the Differential Diagnosis for Vitamin D Toxicity?

• Thyrotoxicosis.

• Hypercalcemia of malignancy.

• Paget disease.

• Vitamin A toxicity.

• Hypercalcemia due to prolonged immobilization.

• Milk-alkali syndrome.

• Hyperparathyroidism.

Conclusion

Vitamin D toxicity is a severe condition that can cause potential damage to the body's organs and be fatal. Vitamin D supplements are readily available over the counter to treat certain medical conditions. But with potential benefits, the vitamin can cause severe toxicity in the body due to overdose or overconsumption by the person without proper knowledge. Therefore, the doctor should prescribe vitamin D to the patient with utmost precaution and continuous monitoring of the supplement dose taken by the patient. Patients receiving high-dose vitamin D supplements are at increased risk of developing fatal outcomes. Therefore, a person should take the supplements as prescribed by the doctor. If symptoms of vitamin D toxicity are experienced, one must contact the doctor immediately to avoid fatal consequences.