Why Do We Need Vitamin A?

Vitamin A (Retinoids) is a family of fat-soluble compounds that play an important role in vision, bone growth, reproduction, promotes healthy surface linings of the eyes and the respiratory, urinary, and intestinal tracts.

Vitamin A was the first fat soluble vitamin to be identified. As opposed to be being one distinct biomolecule, vitamin A is actually composed of a family of substances known as retinoids.  Retinol (alcohol form), retinal (aldehyde form), and carotenoids (previtamin A). There are several carotenoids (a-carotene, cryptoxanthin, lutein, & lycopene), but the one with the most vitamin A activity is beta carotene.

Signs & Symptoms of Vitamin A Deficiency:
Poor immune function
Loss of night vision.
Reduced white blood cell counts
Infertility.
Poor growth
Skin lesions (eczema).
Acne.

Vitamin A has been shown to be beneficial in the following conditions:
Gastric ulcers
Congestive heart failure
Cystic Fibrosis.
Gout
Measles.
Hepatitis
Upper respiratory infections.
Urinary tract infections
Diabetes.
Arthritis
Dermatitis.
Psoriasis
Atherosclerosis.
The common cold
Allergies.

Drugs or additives that may deplete or interfere with Vitamin A metabolism:
Alcohol
Corticosteroids and other medications that interfere with zinc absorption (see zinc)
Neomycin.
Olestra (a food additive found in many fat free products)
Mineral oil (when taken consistently in higher doses).
Cholestyramine.
Colesevelam (Welchol)
Colestipol.

Laboratory testing for Vitamin A:
HPLC (high performance liquid chromatography) – serum blood draw.
Leukocyte functional assays.

Vitamin A Food Sources:
Liver, cod liver oil, yellow and green leafy vegetables, eggs, and dairy products.