Vitamin A (Retinol)...

 Retinol(Vitamin A)

• Vitamin A also stimulates the production and activity of white blood cells, takes part in remodeling bone, helps maintain healthy endothelial cells (those lining the body’s interior surfaces), and regulates cell growth and division such as needed for reproduction.

• The two main forms of vitamin A in the human diet are preformed vitamin A (retinol, retinyl esters), and provitamin A carotenoids such as beta-carotene that are converted to retinol.

 

• Preformed vitamin A comes from animal products, fortified foods, and vitamin supplements. Carotenoids are found naturally in plant foods.

 

• There are other types of carotenoids found in food that are not converted to vitamin A but have health-promoting properties; these include lycopene, lutein, and zeaxanthin.

1) Daily Requirement : 

• Adult : 600 -700 mg
• Infant : 400 - 600 mg

2) Sources :

• Carrot,spinach,tomato and yellow fruits.
• Liver oil ,fish oil, Vegetable Oil
• Many breakfast cereals, juices, dairy products, and other foods are fortified with retinol (preformed vitamin A). Many fruits and vegetables and some supplements contain beta-carotene, lycopene, lutein, or zeaxanthin.
• Leafy green vegetables (kale, spinach, broccoli), orange and yellow vegetables (carrots, sweet potatoes, pumpkin and other winter squash, summer squash)

3) Functions :

• Essential for normal vision
• plays role in growth and reproduction
• Take part in bone and Teeth formation 

4) Effects of Deficiency :

• Vitamin A deficiency is rare in Western countries but may occur. Conditions that interfere with normal digestion can lead to vitamin A malabsorption such as celiac disease, Crohn’s disease, cirrhosis, alcoholism, and cystic fibrosis. Also at risk are adults and children who eat a very limited diet due to poverty or self-restriction.  Mild vitamin A deficiency may cause fatigue, susceptibility to infections, and infertility. The following are signs of a more serious deficiency.

  • Xerophthalmia, a severe dryness of the eye that if untreated can lead to blindness
  • Nyctalopia or night blindness
  • Irregular patches on the white of the eyes
  • Dry skin or hair
• Night blindness
• bitot's spots
• Conjuctional xerosis
• Keratomalacia
• Dermatitis