Hypervitaminosis A and D: Symptoms, Side Effects and Treatment

Hypervitaminosis is a condition caused due to excess storage of one or more than one vitamin in the body leading to toxic symptoms. Vitmains can be water soluble and fat soluble. Fat soluble vitamins are stored in the body where as water soluble vitamins are not stored and they pass out through urine if in excess.

Toxicity usually occurs from fat soluble vitamins, especially from large intake of vitamin supplements. Fat soluble vitamins are vitamin A, D, E and K. Water soluble vitamins are group of vitamin B and C. Hypervitaminosis does not usually occur from eating natural foods. However, toxicity of vitamin can be caused by eating foods that are highly fortified with vitamins. Hypervitaminosis from fat soluble vitamin is more common with vitamin A and D as compared with E and K. Let us know the cause, symptoms and treatment of hypervitaminosis.

As mentioned earlier, hypervitaminosis mainly occurs from excessive storage of fat soluble vitamins such as vitamin A and D and rarely from vitamin E and K.

It mainly occurs due to intake of large amount of vitamin supplement or fortified food and not due to eating natural food containing vitamins.

Hypervitaminosis A:

Vitamin A is stored in liver. When there is too much of vitamin A in the body, it causes symptoms of hypervitaminosis A. The condition can be acute or chronic. Acute hypervitaminosis A occurs due to large amount of vitamin A in limited period of time that is within a span of few hours. Chronic toxicity from vitamin A develops as a result of slow build up of this vitamin in large amount in liver over a period of time.

Symptoms of Hypervitaminosis A:

Acute hypervitamoinosis: The symptoms may occur due to overdose of vitamin supplements or from eating certain foods such as polar bear liver which is densely packed with vitamin A. In majority of cases it is caused due to rapid vitamin overdose. Symptoms include: Headache, nausea, vomiting, lethargy, impaired consciousness and pain in abdomen. More serious symptoms include raised intracranial pressure, vision problem due to edema around the retina, and double vision.

Chronic hypervitaminosis A: It occurs when more than 50000 IU/day of vitamin A is ingested for more than three months. Usually supplementary vitamin A. Symptoms mainly are related with bone problems such as bone pain, yeloow discoloration of skin, hypercalcemia, patchy loss of hair, nausea, vomiting, malaise, enlarged spleen and liver, increased intracranial pressure etc.

Treatment of Hypervitaminosis D:

The most effective treatment is to stop taking high dose of vitamin A supplements. Majority of people recover after stopping the intake within few weeks. Yellow discoloration of skin reverses after a period of time.

Hypervitaminosis D:

Usually it is caused due excessive ingestion of prescribed medications containing calcium and vitamin D. Hypervitaminosis D does not occur due to excessive exposure to sunlight.

Symptoms of hypervitaminosis D: The symptoms are non specific. They occur due to secondary hypercalcemia, because of raised level of calcium in the blood. This will lead to high incidence of kidney stones and calcification of vessels. Vascular calcification can occur in heart vessels or any other vessels. Taking vitamin D for long time more than the dose required can have adverse effect on heart, pancreas, and bones. It may increase risk of heart attacks, fractures etc.

Symptoms of Hypervitaminosis D:

  • Frequent urination
  • Increased thirst
  • Vomiting and nausea
  • Loss of appetite
  • Fatigue
  • Constipation
  • High blood pressure
  • Seizures


The most effective treatment is to stop taking vitamin D supplement if a person has hypervitaminosis D. The symptoms can be brought back to normal if hypervitaminosis D is recognized in its early stage.

From the above fact it is clear that vitamin supplements must not be taken in excess, especially fat soluble vitamins. Unlike water soluble vitamins, fat soluble vitamins are stored in the body for long period of time. They are not excreted out from urine. It takes massive amount of water soluble vitamins to present toxicity. The adverse side effects from hypervitaminosis are reversible if the condition is detected early. Thus vitamin supplements must be taken with caution although nowadays much emphasis is made for taking vitamin supplements.