• Night blindness
• Keratomalacia
• Pale, dry skin

! bgcolor="#ffeedd" colspan="2" | Excess symptoms

• Liver toxicity
• Dry skin
• Hair loss
• Teratological effects
• Osteoporosis (suspected, long-term)

! bgcolor="#ffddaa" colspan="2" | Common sources

• Liver
• Dairy products
• Darkly colored fruits
• Leafy vegetables

Vitamin A (Retinol)
General
Chemical formula	C20H30O
Molecular weight	286.456 g/mol
Vitamin properties
Solubility	Fat
RDA (adult male)	900 µg/day
RDA (adult female)	700 µg/day
RDA upper limit (adult male)	3,000 µg/day
RDA upper limit (adult female)	3,000 µg/day
Deficiency symptoms

Retinol, the dietary form of vitamin A, is a fat-soluble, antioxidant vitamin important in vision and bone growth. It belongs to the family of chemical compounds known as retinoids. Retinol is ingested in a precursor form; animal sources (milk and eggs) contain retinyl esters, whereas plants (carrots, spinach) contain pro-vitamin A carotenoids. Hydrolysis of retinyl esters results in retinol while pro-vitamin A carotenoids can be cleaved to produce retinal. Retinal, also known as retinaldehyde, can be reversibly reduced to produce retinol or it can be irreversibly oxidized to produce retinoic acid. The best described active retinoid metabolites are 11-cis-retinal and the all-trans and 9-cis-isomers of retinoic acid.

Discovery

---

In 1913, Elmer McCollum, a biochemist at the University of Wisconsin, and colleague Marguerite Davis identified a fat-soluble nutrient in butterfat and cod liver oil. Their work confirmed that of Thomas Osborne and Lafayette Mendel, at Yale, which suggested a fat-soluble nutrient in butterfat, also in 1913 Semba RD. Vitamin A as "Anti-Infective" Therapy, 1920–1940. Journal of Nutrition. 1999;129:783-791. PMID 10203551. Full Text Available. Vitamin A was first synthesized in 1947.

More on [ Retinol ]

Vitamin A - Twitter Search

@NotUrAverage_B "Vitamin A is well known for maintaining healthy cells in the eye, required for healthy eyesight." http://t.co/mmiU6vPv
ameen_032 (ameen abu hamdeh) Wed, 01 Feb 2012 21:53:36 -0000
@NotUrAverage_B "Vitamin A is well known for maintaining healthy cells in the eye, required for healthy eyesight." http://t.co/mmiU6vPv
@LanaDelRey pick me up and FOLLOW me like a vitamin, cause my body's sweet like sugar in the morning yeah6
DiegoRoses_ (Diego Rosés.) Wed, 01 Feb 2012 21:53:33 -0000
@LanaDelRey pick me up and FOLLOW me like a vitamin, cause my body's sweet like sugar in the morning yeah6
@HeyyItsDevin Vitamin E is a wound treating vitamin. It is v Subscribe to Vitamin_A RSS feed