Vitamin A is known as retinol and occurs only in animal products.

Plants have a yellowish dye known as beta-Carotene (provitamin) which in animal cells can be easily split into two molecules of vitamin A.

RETINOL C20H29OH

BETA-CAROTENE C40H56

soluble in fat

relatively stable

sensitive to the light

sensitive to oxygen (administered with vitamin E which is antioxidant)

play an important role in vision, bone growth, reproduction, cell differentiation and cell division.

helps regulate the immune system which helps prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses.

help lymphocytes fight infections more effectively.

Better absorption of vitamin A will give us:-the presence of fat-vitamin D-complex vitamins of the B group-vitamin C-vitamin E-calcium-zinc-phosphorus

Worse absorption of vitamin A:-sodium benzoate,-vitamin D -deficiency,-caffeine,-nicotine,-alcohol,-nitrites,-steroids-laxatives,-damaged pancreas.

Medicine

In the treatment of:-acne-Stretch marks-dyskeratosis-psoriasis-photoaging of the skin

-lack of vitamin A

In cosmetiscs-creams

-lotionsThese cosmetiscs are very helpful for people with skin problems.

egg butter cod-liver oil cheese whole milk fish meat spinach grapes carrote yellow pumpkin tomatos avocado

liver abnormality (symptoms of poisoning)

central nervous system disorders

birth defects

reduced bone mineral density that may result in osteoporosis

skin changes

respiratory infections

anemia and apathy

increased intracranial pressure

night blindness

damaged cornea of eye

inhibition of growth

http://www.witaminaa.com.pl/wchlanianie-witamina-a/

http://portal.abczdrowie.pl/naturalne-wystepowanie-witamin

http://www.biotechnologia.uni.opole.pl/biblioteka/docs/WITAMINY-PRAWDA-I-MITY.pdf

http://forumsportowe.us/viewtopic.php?t=179 http://www.nhs.uk/Conditions/vitamins-

minerals/Pages/Vitamin-A.aspx http://jejzdrowie.pl/dzialanie-witaminy-a Claude A.Villee- „Biologia” Phil Bradfield and Steve Potter -LONGMAN

GCSE Biology

Weronika Kielar Karolina Grzeszek Magdalena Adamowicz Karolina Kurys

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