HN 132 Lecture 16 Outline of Last Lecture I. Best food sources of protein II. Too Much ProteinIII. Too Little ProteinIV. PEMV. Too little protein leads to…VI. Not all protein created equal Outline of Current LectureI. What are vitamins?II. Vitamin ACurrent LectureI. What are vitamins?A. Vitamins are essential nutrients1. Tasteless, organic compounds needed in small amounts2. A deficiency will cause physiological symptomsB. Consuming too much of some vitamins will cause adverse effectsC. Vitamins are either fat-soluble or water-soluble1. Fat-soluble vitamins A, D, E, and K are absorbed with dietary fat and can be stored in body2. Water-soluble vitamins are absorbed with water and enter the bloodstream directlya. Not stored in body, but excesses still harmfulD. Vitamins differ in bioavailability, which is the degree to which a nutrient is absorbed from foods and used in the body.1. Vitamins can be destroyed by air, water, or heat2. Don’t expose your produce to airThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.3. A little water is enough4. Reduce cooking time5. Keep your food coolE. Overconsumption of some vitamins can be toxicF. Provitamins can be converted to vitamins by the bodyG. Some vitamins function as antioxidants, substances that neutralize free radicals. 1. Vitamins A, C, and E, and beta-carotene are antioxidants2. Free radicals are molecules with unpaired electrons that can damage the cells of the body and possibly contribute to the increased risk of chronic diseasesII. Vitamin AA. Vitamin A: retinoids (retinol, retinal, retinoic acid)B. Preformed vitamin A only found in animal foods: liver, eggs, fortified milk, cheeseC. Some plants contain provitamin A carotenoids, which are converted to retinol in your body.1. Carotenoids, including beta-carotene, are pigments which give color to carrots, cantaloupe, sweet potatoes, spinach, broccoli.a. Like fat-soluble vitamins, absorbed more efficiently if fat present inintestinal tractD. Functions:1. Essential for healthy eyesa. Component of rhodopsin and iodopsin, light-sensitive proteins needed for vision2. Involved in cell differentiation, reproduction, and immunity by promoting gene expression for:a. Healthy skin, mucus membranesb. Bone growthc. Fetal developmentd. White blood cells to fight harmful bacteriaToo much or too little:3. Excessive amounts of preformed vitamin A can accumulate to toxic levels a. Upper limit for adults: 3,000 µg 4. Carotenoids in food are not toxicb. Excess carotenoids cause nonthreatening condition: carotenodermiac. Chronic vitamin A deficiency causes night blindnessd. Prolonged vitamin A deficiency leads to xerophthalmia e. Number-one cause of preventable blindness in children, mostly in developing countriesf. As many as 500,000 children go blind each year due to vitamin A deficiency g. Vitamin A deficiency also associated with stunting of