Hypervitaminosis A (Vitamin A Toxicity)

The Biochemistry Online – Free Online Lectures for Medical, Dental and Allied Health Sciences students by the Biochemistry Club.

Vitamin A is classified in Fat Soluble Vitamins. It comes in from various sources. It is also a very strong antioxidant. All Fat Soluble Vitamins are stored in our body. Excessive intake of Vitamin A can lead to toxicity because the Vitamin A is stored. It has been reported in children where parents have been overzealous in supplementing the vitamins. Eskimos refrain from eating the liver of polar bear due to its high Vitamin A content. 

Symptoms of toxicity include:

1. Anorexia
2. Irritability
3. Headache
4. Peeling of skin
5. Drowsiness
6. Vomiting
7. Some of these signs are due to increased intracranial tension.
8. Sometimes swelling over long bones (bony exostosis) may occur with painful bones.
9. Enlargement of liver is also seen in children.
10. Higher concentration of retinol increases lysosomal enzymes, leading to cellular death.
11. Hypercarotenemia can result from persistent excessive consumption of foods rich in carotenoids.
12. The skin becomes yellow, but no staining of sclera as in jaundice is observed.

All these lectures are organized and listed in detail in their proper sections. To view these lessons please visit the Vitamins Section in Biochemistry I. This can be approached by directly clicking the Biochemistry I button or it can also be approached from the drop down menu in Biochemistry I tab. Once you reach the section click the curriculum tab to view the full list in the section.

Any further questions or inquiries are welcome.

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