Fat Soluble Vitamins

Vitamins can be divided into those that are soluble in water (water-soluble) and those that are soluble in fat (fat-soluble).The fat soluble vitamins include vitamins A, D, E and K and these are absorbed through the large intestines.

 

Fat soluble vitamins need the presence of fats and certain minerals to be absorbed by the digestive system and are stored mainly in the liver and fatty tissues.  Since they are stored in the body, they do not need to be consumed as regularly as water soluble vitamins but pose greater risk of toxicity when taken in excess.

 

FAT SOLUBLE vitamins are listed below along with their brief advantages:

 

VITAMIN A

Vital to good vision
Prevents night blindness
Necessary for healthy skin and hair growth
Keeps mucous membranes healthy

 

VITAMIN D

Promotes hardening of bones and teeth
Increases the absorption of calcium

 

VITAMIN E

Helps breakdown polyunsaturated fats
Protects blood cell membranes from overexposure to oxygen
Antioxidant

 

VITAMIN K

Essential for clotting of blood
Found in foods and manufactured by Vitamin K producing bacteria in the small intestines

 

ABSORPTION AND TRANSPORTATION
The absorption of fat soluble vitamins requires adequate absorption of dietary fat as well as bile salts. Bile is a substance produced by the liver and stored / released by the gall bladder. Bile consists of salts, acids, cholesterol, lipids, pigments, and water.  Bile salts help lipase in the emulsification, digestion and absorption of fats.

 

Since bile increases the absorption of fats, it is an important part of the absorption of the fat soluble substances including fat soluble vitamins (A, D, E and K).

 

The absorption of fat soluble vitamins also require chylomicrons which are lipoprotein particles of triglycerides produced in the intestines during digestion and transport dietary lipids from the intestines to other locations in the body.

 

Thus absorption and transportation of fat soluble vitamins depend on dietary fat, bile salts and chylomicrons.