Toxicity of Vitamin D in Improper Doses

Since the start of the COVID-19 pandemic, there has been increasing talk about vitamin D. Many studies have pointed to a connection between the virus and this vitamin, and in most cases, vitamin D supplements have been part of regular therapy for treatment and recovery. However, vitamin D is extremely important for overall health, regardless of whether the body is affected by an illness or not. Still, taking excessive amounts of vitamin D over the long term can be toxic. Experts from IntroLab laboratory, one of the best laboratories in Belgrade, reveal the symptoms and actual toxicity of vitamin D in improper doses.

What Is Vitamin D?

Vitamin D is an essential vitamin, which is actually a hormone necessary for the normal development and maintenance of bone mass. It also plays an important role in the nervous, musculoskeletal, and immune systems. The body converts consumed vitamin D into its “active” form, which helps with calcium absorption.

There are several ways to ensure adequate amounts of vitamin D:

  • Exposure of the skin to sunlight.
  • Through the food and drinks you consume.
  • With the help of dietary supplements and prescription medications.
A person taking medicine
Vitamin D is obtained, among other things, from drugs

What Is Vitamin D Toxicity?

Vitamin D toxicity, known as hypervitaminosis D, occurs when there is an excessive amount of vitamin D in the body. This rare complication usually arises from taking larger doses of vitamin D than prescribed or from the excessive use of over-the-counter dietary supplements. Too much vitamin D can lead to hypercalcemia, meaning that calcium levels in the blood are higher than normal, causing various symptoms. Although death is rare in cases of vitamin D toxicity, this condition can significantly threaten health. In severe cases, it can lead to kidney failure, arrhythmia, unsteady walking, and confusion.

What Is a Toxic Level of Vitamin D?

The dose of vitamin D that can cause toxic symptoms varies significantly. Toxicity can occur at just 2,000 units per day (IU/day) in sensitive individuals.

  • Recommended daily doses of vitamin D include:
  • Individuals aged 19 to 50 years: 600 IU/day.
  • Individuals aged 50 to 70 years: At least 600 IU/day.
  • Individuals over 70 years: At least 800 IU/day.

The maximum recommended daily dose for healthy adults is 4,000 IU/day.

Talk to your healthcare provider if you are concerned about your vitamin D intake. They can provide guidance on whether you should take a supplement and in what amount, as well as alternative ways to improve poor immunity.

Vitamins in a box
Vitamin D toxicity occurs due to the excessive use of dietary supplements

What Causes Toxicity?

Toxicity of vitamin D usually occurs due to excessive intake of prescription vitamin D or excessive use of over-the-counter vitamin D supplements. If you are taking supplements, it is recommended to regularly check your vitamin D levels through a vitamin D blood test.

Excessive sun exposure cannot cause vitamin D toxicity. Additionally, it is very rare for excessive vitamin D intake solely from food to lead to toxicity.

What Are the Main Symptoms?

Symptoms of vitamin D toxicity are mainly due to hypocalcemia and include:

  • Reduced appetite
  • Nausea and vomiting
  • Constipation
  • Dehydration
  • Increased thirst (polydipsia)
  • Frequent urination
  • Confusion, lethargy, and fatigue
  • Muscle weakness and difficulty walking
  • Bone pain
  • Kidney stones

When Is There an Increased Risk of Toxicity?

People who use prescription vitamin D are at risk of toxicity due to high doses of this medication if they do not regularly monitor their levels. Some health problems that require high doses of vitamin D include:

  • Vitamin D deficiency that does not respond to lower doses
  • Osteoporosis
  • Osteomalacia
  • Renal osteodystrophy
  • Psoriasis
  • Gastric bypass surgery
  • Celiac disease and other disorders causing poor absorption of vitamin D
  • Inflammatory bowel disease
  • Multiple sclerosis

When treating these conditions, it is important to ensure that the recommended amounts of vitamin D are not exceeded, as this can cause numerous new problems, as previously mentioned.

How Is the Diagnosis Established?

The diagnosis of vitamin D toxicity is based on a combination of several factors. Healthcare professionals first analyze the patient’s symptoms, as well as their history of medication and dietary supplement intake. Laboratory tests are used for a more precise diagnosis, including measuring vitamin D levels and analyzing calcium in the blood. Additionally, kidney function tests are performed to determine their operation, which can be significant in the context of vitamin D toxicity.

Blood ready for vitamin D toxicity analysis
Check your vitamin D blood levels regularly

Treatment and Prevention

Treatment for vitamin D toxicity focuses on reducing calcium levels in the blood. Healthcare providers will stop your intake of all vitamin D and calcium supplements until the condition stabilizes. Intravenous fluids will be used to treat dehydration. In severe cases of toxicity, corticosteroids and bisphosphonates, which prevent bone resorption, may be administered. If severe kidney damage occurs, hemodialysis may be necessary to remove excess calcium.

When it comes to preventing vitamin D toxicity, it is important to carefully plan and monitor your intake of this vitamin. Before starting any supplements, it is necessary to consult with a healthcare professional. It is crucial not to exceed the doses recommended by your doctor, whether it involves dietary supplements or prescribed medications. Regular laboratory tests will help monitor vitamin D levels and prevent potential complications. Also, store your supplements and medications in a safe place that is out of reach of children and pets to avoid accidental use.

This Condition Is Not Common

Taking excessive amounts of vitamin D supplements or prescribed medications can cause toxicity of vitamin D. The good news is that this complication is relatively rare and usually does not cause long-term problems once treated. If you have questions about how to ensure you get enough vitamin D or other nutrients, talk to your healthcare provider. They are there to help you.

This site is registered on as a development site.