Vitamin A Overdose – Side Effects, Symptoms & Treatment

Health Care Guide on Vitamin A overload Amount, death effects, Symptoms in Children & Pregnancy with Treatment & Medication 

TOXICITY :

Hypervitaminosis A

Excessive intake of vitamin A affect:-

• CNS : headache, nausea, ataxia, anorexia, increased intracranial CSF pressure.
• Liver : hepatomegaly with histologic changes and hyperlipidemia.
• Calcium hemeostasis : thickening of long bones, hypercalcemia and calcification of soft tissues.
• Skin : excessive dryness, desquamation and alopecia.
• Mucous membrane defects

Vitamin A Deficiency, Symptoms & Treatment

Presentation Notes on Vitamin A disorder / Diseases (Skin, Hair Loss, Night Blindness, Oral Structure & Tung) Causes, Diagnosis & Treatment Dose in India in word/ .ppt Format  

Clinical manifestation of deficiency of vitamin A :

Vitamin A deficiency may be caused by a decreased dietary intake, however, this is usually seen in very severe malnutrition. It may also occur secondary to fat malabsorption.

In the eye symptoms are progressive. The earliest sign of deficiency is a loss of sensitivity to green light, followed by impairment to adaptation to dim light, followed by night blindness. This is reversible.

Vitamin A Functions

Presentation Notes of Functions of Vitamin A in Human Body with Details of Vitamin A functional Groups for Student & Kids in word/ .doc /.ppt Format

Functions of vitamin A :

There are 3 active forms of vitamin A

• Retinoic acid
• Retinaldehyde
• b-carotene

1)   Retinal has a role in Vision : In the pigment epithelium of the retina, all-trans-retinol is isomerized to 11-cis-retinol and oxidized to 11-cis-retinaldehyde. This binds to opsin to form rhodopsin, the visual pigment of the rod cells in the retina involved in vision and dark adaptation to light.

About Vitamin A – Chemistry, Absorption, Utilization and Storage

Presentation Notes on Vitamin A Chemical Composition, Absorption, Storage & Utilisation in Human Body for Students & Kids in word/ .ppt/ .doc Format

Chemistry:

Vitamin A is a pale yellow, almost colorless compound soluble in fat or fat solvents and insoluble in water. Because of its high degree of unsaturation, the vitamin A content of fats and oils can be destroyed by oxidation as the fats and oils become rancid. Protection by antioxidants such as vitamin E or storage in a cool, dark place will prevent the oxidation and rancidity.

The vitamin A found in animal foods has two slightly different forms, vitamin A₁ and vitamin A₂. Vitamin A₁ is found chiefly in the liver and body fat of fish and in other foods of animal origin such as liver, milk, butter, and egg yolk. Vitamin A₂ which is of little importance in human nutrition, is found in fresh-water fish.

Vitamin A Rich Foods Sources

Health Care Guide on Vitamin A Rich Food Lists for Kids & Adults with Vitamin A History & Recommended daily intake

VITAMIN A

Discovery: Night blindness was cured in ancient Greece either by ingesting cooked liver or by applying topically to the eyes the juice squeezed from cooked liver.

           

In 1913 two teams of chemists McCollum and Davis, and Osborne and Mendel extracted an accessory food factor from butterfat by the use of ether, thus proving that it was fat soluble. McCollum and Davis called it fat-soluble A. C.E. Bloch, a Danish physician, noted that xerophthalmia in children could be cured by the addition of a milk product to their diet.