How Much Vitamin D Is Too Much?

Medically Reviewed on 8/31/2021
vitamin d overdose
Restricting vitamin D intake to less than 4,000 IU per day for adults and between 1,000 IU to 3,000 IU for children under 8 years old can help prevent vitamin D overdose.

Excessive intake of vitamin D can lead to various health problems. The maximum safe intake or the upper limit of vitamin D varies according to factors, such as age and special situations (pregnancy, lactation). Studies suggest that intake of more than 5,000 international units (IU) of vitamin D per day may cause chronic toxicity in adults. In infants, younger than six months old, amounts as low as 1,000 IU per day could be harmful.

Table. The daily upper limit of vitamin D from all sources (including supplements and diet)
Age group The daily upper limit of vitamin D
0 to 6 months 25 mcg* (1,000 IU**)
7 to 12 months 38 mcg (1,500 IU)
1 to 3 years 63 mcg (2,500 IU)
4 to 8 years 75 mcg (3,000 IU)
9 years and older 100 mcg (4,000 IU)
Special situations
Pregnancy 100 mcg (4,000 IU)
Lactation (breastfeeding) 100 mcg (4,000 IU)
*Micrograms **International units

What are the signs of excessive vitamin D in your body?

Excessive vitamin D or vitamin D toxicity may cause the following signs and symptoms:

Extremely high levels of vitamin D can lead to serious conditions, such as kidney failure, irregular heartbeat (arrhythmia) and even death if left untreated.

The symptoms of vitamin D toxicity in infants and young children can present differently than in adults. Infants may become lethargic or drowsy, while also showing signs of poor feeding and inconsolable crying. Toddlers may present with symptoms, such as vomiting, irritability and constipation. Additionally, they may have a raised blood pressure (hypertension) on clinical examination.

What is the cause of vitamin D toxicity?

Vitamin D toxicity typically occurs due to excessive intake of vitamin D supplements and does not occur due to dietary intake of vitamin D or sun exposure. This is because the intake of the vitamin through foods, including fortified foods, is not sufficient enough to cause toxicity. Furthermore, the body regulates the production of vitamin D due to sun exposure. Essentially, natural sources do not cause vitamin D toxicity.

How is vitamin D toxicity diagnosed?

Doctors diagnose vitamin D toxicity through the following ways:

  • Taking a detailed medical history
  • Performing a thorough physical examination
  • Conducting investigations, such as
    • Electrocardiogram to look for the signs of excessive calcium in the blood or hypercalcemia caused by excessive vitamin D
    • Blood tests including serum calcium, vitamin D levels and kidney function tests
    • X-ray

What is the treatment for vitamin D toxicity?

Vitamin D toxicity (hypervitaminosis D) treatment mainly involves the following:

  • Stopping the further intake of vitamin D
  • Restricting calcium intake in the diet
  • Oxygen support
  • Increasing excretion of calcium through stools by administering calcium disodium edetate orally
  • Intravenous fluids
  • Diuretics or water pills
  • Other medications, such as corticosteroids, bisphosphonates, calcitonin and mithramycin
  • Dialysis (peritoneal or hemodialysis) could be needed in some patients
  • Other treatment measures for symptomatic relief


Vitamin D Deficiency: How Much Vitamin D Is Enough? See Slideshow

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Medically Reviewed on 8/31/2021
Rosenbloom M. Vitamin Toxicity. Medscape.

National Institutes of Health. Vitamin D.