4. Vitamin A and β-CaroteneA. Definition/classification Lipid SolubleB. Vitamin A~ Has 2 forms- (know) Pro-vitamin form = β-Carotene (precursor to vitamin A)C. Carotenoids1) A phytochemical2) Many different types 3) Highly colored compound (makes leaves yellow, orange, etc.)4) β-Carotene (Pro-Vitamin): can be made into Vitamin A by the human body Most of the Vitamin A in the human body is from beta-caroteneD. Functions1) Vitamin A:  Vision (especially Night Vision)* Cell differentiation~ Used during prenatal development to control what cells become ~ Too much can cause problems Bone health Immune Function Antioxidant2) Carotenoids Conversion to Vitamin A (some)~Limits conversion to prevent toxicity Antioxidant ~especially for lipoproteins such as LDLE. Deficiency signs/symptoms1.2.3.~4.~F. Groups at risk (from deficient Vitamin A)1. Infants & young children in developing countries worldwide causing Retardation (still very major preventable problem)2. People eating very little fat3. People with fat malabsorption~ Cystic Fibrosis and AIDSG. Dietary Sources1. Vitamin A Eggs Liver2. Carotenoids Dark green vegetables Dark Orange Fruit~ Deep Orange vegetables~H. Special Notes1. Needs varies with body weight, especially body fat2. Toxicity- can cause birth defects (Need to be careful with acne medications if you are pregnant or going to become pregnant)3. Used as an acne medication (Retin A was the first)4. Used as an anti-wrinkly drug (pregnant women used to get acne medicine to help with wrinkles and this caused birth defects (ACUTANE)5. Used as a chemotherapy