February 06, 2014

Vitamin A

  Vitamin A is a fat-soluble vitamin important to bone growth, vision, reproduction, cell differentiation and division, and immune system regulation. The vitamin also helps prevent infection by producing white blood cells and is important for healthy skin and mucous membranes, according to the Office of Dietary Supplements.

Functionality

    Vitamin A is referred to be a vitamin for growth and body repair. Healthy formation of bones, teeth, skin; maintenance of outer layer of many tissues and organs; promotes growth and vitality; essential in pregnancy and lactation; necessary for night vision; good for growth and repair of body tissues; good for health of hair and eyes, and also keeps your skin smooth.

    Vitamin A works together with vitamins D, B, E, zinc, phosphorus and calcium. It also acts as an antioxidant, which may help protect against cancer and other diseases.

Rich Sources




    There are two forms of vitamin A available from dietary sources: preformed vitamin A (retinol), which is found in animal products, and provitamin A (beta carotene), which is found in produce (fruits and vegetables)
  • Retinol is found in highest concentrations in fish liver oil, liver from chicken or beef, Egg yolks and milk products such as whole milk, cream and butter.
  • Provitamin A, also known as beta carotene, is the double molecule form of retinol. It is subsequently converted to retinol within the body. Vegetables that are yellow and orange in color are the highest in vitamin A, along with dark leafy vegetables. Carrots, pumpkins and yams are all in this category.
  • People who limit their consumption of liver, dairy foods, and beta-carotene-containing vegetables
  • Extremely low birth weight babies
  • High Consumption of Iron supplements
  • Black Tea (Tannic Acid)
  • Aspirin and Nitrates from processed meats 
  • Insufficient intake of Zinc, Vitamin E
  • Lifestyle factors, including smoking, fast food, excess alcohol

    Alternatively, leafy greens such as lettuce, spinach and kale are also good sources of vitamin A. other sources – butternut squash, cantaloupe, Collards (rich source of Ca), dried herbs (Dried Basil, Dried Parsley, Marjoram, Dried Oregano, Dried Coriander and Fresh Thyme)

   Similar to vegetables, fruits that are valuable sources of vitamin A are yellow, orange and red. These include apricots, cherries, mangoes and peaches. The edible skins of these fruits contain higher amounts of vitamins than the flesh

Recommended Daily Intakes

Men - Normal - upto 25,000 IU (7,500 mcg)
           Men over age 65 - 15,000 IU per day

Women - Less than 10,000 IU (3000 mcg) per day

Deficiency Disease

   Night-blindness and Keratomalacia, Keratinisation of the nasal and respiratory passage epithelium

Deficiency Symptoms

   Defective Teeth and Gums, Allergies, Dry Hair, Retarded Growth, Susceptibility to Colds and Infections, Night Blindness, Eye Irritations, Sinus Trouble, Dry Skin, Loss of Smell, Acne, sensitivity to light, reproductive problems

Deficiency Occurs in:


  • People who limit their consumption of liver, dairy foods, and beta-carotene-containing vegetables
  • Extremely low birth weight babies
  • High Consumption of Iron supplements
  • Black Tea (Tannic Acid)
  • Aspirin and Nitrates from processed meats
  • Insufficient intake of Zinc, Vitamin E
  • Lifestyle factors, including smoking, fast food, excess alcohol

Overdose Disease

Hypervitaminosis:-  A Too much of the beta-carotene form of vitamin A can cause skin to appear yellow, while too much of the retinol form of vitamin A can cause mild headaches, nausea, dizziness, abdominal pain and hair loss. 

Sources

                     Whereincity
                     Picture

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