Vitamin A

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 Deficiency:

  • Poor immune function
  • Loss of night vision
  • Reduced white blood cell counts
  • Infertility
  • Poor growth
  • Skin lesions (eczema)
  • Acne
  • Fatigue

Vitamin A has been shown to be beneficial in the following conditions:

  • Gastric ulcers
  • Hypothyroid
  • Congestive heart failure
  • Cystic Fibrosis
  • Gout
  • Measles
  • Hepatitis
  • Upper respiratory infections
  • Urinary tract infections
  • Diabetes
  • Arthritis
  • Dermatitis
  • Psoriasis
  • Atherosclerosis
  • The common cold
  • Allergies

Drugs, medications, 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 (Spectracell labs)

Food Sources:

  • Liver, cod liver oil, yellow and green leafy vegetables, eggs,and dairy products