VITAMIN A (PDF)

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					                                                                                                                                 VITAMINS
                    V I TA M I N A
                                                                                                             VERSION 1.0




What is it?
Vitamin A is a fat-soluble vitamin. There are different
forms of vitamin A including retinol, retinal, retinoic
acid, and retinyl ester, which are collectively referred to
as ‘retinoids’. The strongest form of vitamin A is retinol.

Why you may need vitamin A
Acne, eczema, psoriasis – vitamin A is important for
maintenance of epithelial tissue, which covers the
external surface of your body – your skin.

Cataracts – a high dietary intake of vitamin A is
associated with a reduced risk of cataracts.

Urinary, respiratory, gastrointestinal and vaginal
infections – vitamin A assists immune function and             Doses used in clinical trials
increases resistance to infection. The linings inside our      10,000–25,000 IU daily for up to two weeks has been
body are made up of epithelial tissue called mucous            used in adults with clinical deficiency of vitamin A.
membranes. These include linings of the mouth, nose,
stomach, intestines, lungs, bladder and vagina.                Symptoms of deficiency
Vitamin A is important for helping to maintain healthy         Symptoms of deficiency include the following – night
mucous membranes. Changes in this lining can                   blindness, xerophthalmia (the cornea and conjuctiva
increase the susceptibility to infection.                      become dry, thick and wrinkled), bitots spots
                                                               (triangular grey spots on the eye), visual impairment
Breast cancer – studies have found a link between              and blindness, dryness of the skin, plugged hair
high dietary intake of vitamin A and a reduced risk of         follicles, increased susceptibility to respiratory, urinary
breast cancer among pre-menopausal women with a                tract and vaginal infections, kidney stones diarrhea,
family history of breast cancer.                               loss of appetite, anemia, stunted bone growth in
                                                               children and tooth decay.
Anaemia – vitamin A deficiency can impair iron
mobilisation from body stores.                                 Food sources
                                                               The best dietary sources of vitamin A include eggs,
How much do you need?                                          whole milk, butter, meat, animal liver and fish liver oils
Recommended Daily Intake (RDI)                                 eg cod and halibut (the liver stores retinol – vitamin A).
Adults (over 19 years): 2500 IU (750 mcg) daily
Pregnancy: 2500 IU (750 mcg) daily                             Other reasons why you may need more
Breastfeeding: 4000 IU (1.2 mg) daily                          Good digestion plays a very important role in
Children over 7 years: 1666–2500 IU (500–750 mcg)              maintaining adequate vitamin A levels. You may need
daily                                                          more if you have a malabsorption disorder such as
Children under 7 years: 1000–1415 IU (300–425 mcg)             coeliac disease, cystic fibrosis, pancreatic disease or
daily                                                          cirrhosis of the liver. If fat absorption is difficult for you,
                                                               best to choose a water-miscible vitamin A supplement.

                                                                                                         …..continued over

                        THIS INFORMATION IS NOT INTENDED TO TREAT OR DIAGNOSE. ALWAYS CONSULT YOUR
                         HEALTHCARE PROFESSIONAL BEFORE TAKING NUTRITIONAL OR HERBAL SUPPLEMENTS.
                                                                                                                                VITAMINS
V I TA M I N A                       continued

                                                                                                             VERSION 1.0




  Gastrointestinal infections or infestations such as            Excessive intake of vitamin A (hypervitaminosis) can
  giardia and hookworm can reduce vitamin A                      lead to a deficiency in blood clotting factor thrombin,
  absorption.                                                    causing increased bleeding time. Vitamin K can correct
                                                                 the problem.
  The liver is the main organ that stores retinol.
  Conditions such as marasmus and kwashiorkor are                Since vitamin A is a fat-soluble vitamin it can be stored
  caused by severe protein malnutrition. The liver               and easily accumulated in the body. Always check with
  reduces the release of retinol and doesn’t increase            your healthcare professional when supplementing with
  until protein status has normalised.                           high doses of vitamin A. Toxicity symptoms include
                                                                 severe headache, sore mouth, bleeding gums,
  If you are zinc deficient, your vitamin A levels may not       dizziness, loss of appetite, nausea, vomiting,
  be too crash hot either. Zinc is required in the liver for     diarrhoea, weight loss, blurred vision, irritability,
  synthesis of retinol binding protein and without               fatigue, insomnia, painful bones, dry itchy peeling skin,
  adequate zinc, vitamin A also suffers.                         rashes, cracked lips, hair loss, brittle nails, cessation of
                                                                 menstruation, high calcium and lipids in the blood and
  Safety notes                                                   jaundice.
  Back to the liver – if you have liver disease or drink
  alcohol in excess, there is an increased risk of vitamin
  A toxicity. Your liver can only handle so much!

  High doses of vitamin A have been shown to be cause
  birth defects. Studies have been done to work out the
  threshold. The levels in studies vary from 10,000–
  30,000 IU daily.

  The Therapeutic Goods Administration of Australia
  recommends the following for pregnant women ‘The
  recommended adult daily amount of vitamin A from all
  sources is 2500 IU. When taken in excess of 8,000 IU
  vitamin A can cause birth effects. If you are pregnant,
  do not take vitamin A supplements without consulting
  your doctor or pharmacist.’

  During pregnancy a well balanced healthy diet should
  cover your vitamin A requirements and further
  supplementation should not be necessary. You should
  discuss any conditions you have with your healthcare
  professional to assess if they may influence your
  vitamin A status.

  Large doses of vitamin A increase the need for vitamin
  E to protect against the oxidation effects of vitamin A.


                          THIS INFORMATION IS NOT INTENDED TO TREAT OR DIAGNOSE. ALWAYS CONSULT YOUR
                           HEALTHCARE PROFESSIONAL BEFORE TAKING NUTRITIONAL OR HERBAL SUPPLEMENTS.

				
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