Fat-Soluble Vitamins

• What is Vitamin A?

  Fat-soluble, unsaturated, long chain alcohol which is also known as retinol.
• What is Vitamin A obtained from?

  Animal foods in the form of retinyl palmitate, which is converted into retinol in the ileum (small intestine).
• What is Provitamin A obtained from?

  Plant foods, called carotenoids that are also converted into retinol in the body in the ileum(small intestine).
• What is the most active Provitamin A substance?

  Beta-carotene.
• What colour are Carotenoids?

  Yellow/orange coloured pigments found in plant foods.
• What is Retinol function?

  Retinol is converted to retinal, which is needed by the retina in the eyes. Retinal joins up with a protein called ospin to form the light-sensitive substance called rhodopsin, which enables the eyes to see in dim light.
• What is Retinol other functions?

  Retinol is converted to retinoic acid, which is important growth substance for epithelial cells that line the cavities and surfaces of blood vessels and are found in glands and organs throughout the body.
• What is Vitamin A also involved in?

  Correct working of the immune system and keeping the mucous membranes throughout the body healthy, all which prevents the development of infections, also an important antioxidant.
• What are food sources of Vitamin A?

  Liver, egg yolk, fish oils and dairy products.
• What are food sources of Beta-Carotene?


  Carrots, sweet potatoes, spinach, kale.
• What are the different forms of Vitamin D?

  Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol).
• What are food sources of Cholecalciferol?

  Liver, cod liver oil and dairy products.
• What is Ergocalciferol used for?


  Supplements.
• What is the main function for Vitamin D?


  Production in the body by the action of sunlight on the skin called the biogenesis of Vitamin D. Ultraviolet light from the sun stimulates provitamin D (called 7-dehydrocholesterol), which is just under the skin, to convert to cholecalciferol.
• What is Cholecalciferol converted to?

  25-hydroxycholecalciferol in the liver, and further converted in the kidneys to 1,25-dihydroxycholecalciferol, which is the active form of the vitamin.
• What does the body use to regulate from 1,25-Dihydroxycholecalciferol?

  1.Calcium absorption in the ileum.

  2.Uptake of calcium into the bones.

  3.Amount of calcium ions in the blood.
• What is 1,25-Dihydroxycholecalciferol also involved in?

  Production of red blood cells and the function of the immune system.
• What are the food sources of Vitamin D?

  Sunlight, fatty fish, fortified foods.
• What is the chemical name for Vitamin E?

  Tocopherol.
• What is the main function of Tocopherol?

  Antioxidant, which prevents substances called free radicals that are either taken in by the body or produced by it, picking up oxygen and going on to damage body cells and stop them working properly.
• What are the deficiency’s and excesses of Tocopherol?

  Rare.
• What is the chemical name of Vitamin K?

  Phylloquinone.
• What is Phylloquinone main function?

  Needed for complex blood clotting process that the body uses when it is injured.
• What happens to Phylloquinone in the small intestines?

  Bacteria can convert Phylloquinone to Menaquinone (Vitamin K2).