HES 2823 1st Edition Exam 3 Study Guide Lectures 16 22 Lectures 16 and 17 March 12 and March 24 Introduction to Vitamins and Discussion of Vitamin A What is the purified diet idea and what were its effects What are the fat and water soluble vitamins and their basic characteristics What are the characteristics of vitamins What are the forms functions deficiencies food sources and toxicities of vitamin A What is meant when a food is fortified The purified diet idea was based on the idea that pure sources of nutrients could be mixed together as an early nutritional concept Initially researchers only included pure carbohydrates proteins and fats to the substance causing death to test subjects Adding liver to the diet caused fewer negative side effects and better life spans In 1915 Yale scientists discovered a compound in liver necessary for survival and termed it fat soluble A One of these researchers instituted the first nutrition program on the university level Another scientist soon identified the compound water soluble B containing a vital amine compound which he called a vitamine Even smaller compounds were found within this main compound but the term vitamine became vitamin and was applied to all like compounds These studies lead to standard terminology for water and fat soluble vitamins Fat soluble vitamins A D E and K stored and toxic Water soluble vitamins C B12 B6 folate thiamin riboflavin and niacin not stored and less toxic organic compounds required in small amounts within the diet no energy not a source of kcal Vitamin A has three forms retinol retinal and retinoic acid Retinol is stored in the liver and the only form of vitamin A found in pill supplements but referred to as retintyl palmitate more stabilized Retinal is not found in food and beta carotene is converted into this form Retinoic acid is not found in food but it is used in drugs related to acne skin care and lotions or creams for anti aging Vitamin A is used to make photosensitive compounds within the eye As light enters the eye through the cornea and reaches the retina at the back of the eye the retina containing light sensitive compounds that react chemically sends messages to the brain to interpret and create images It also aids mucus secretion produced by epithelial tissues which line the inside of the body If vitamin A is deficient the tissue becomes keratin secreting a dry and brittle protein The body can store months supplies so this is rare but night blindness can occur in which compounds sensitive to the wavelength of dim light are the first to fail and cause and inability to see in dim light This condition is reversible if no long term has happened Xeropthalmia dry cracked corneas causing light entering the eye to scatter and miss the retina is irreversible and causes blindness In these cases the cornea becomes cloudy or bumpy Liver is a good source of vitamin A as well as beta carotene rich foods have a yellow orange pigment including carrots sweet potatoes cantaloupe papaya mango apricot persimmons and pumpkin pie Milk offers a fortified source If consumed in excess vitamin A can be deadly An intake of 50 times the recommended daily allowance RDA causes acute toxicity usually occurring through pills and supplements Cerebral spinal fluid increases in volume and this pressure builds within the brain instigating headaches delirium coma and possibly death Polar bear liver has enough vitamin A to kill a human Chronic toxicity happens after long term consumption of 4 times the RDA When consistently over consumed the compound enters the blood and acts like soap dissolving membranes To fortify a food is to add a nutrient already present within that food in greater amounts Lecture 18 March 26 Discussion of Vitamins D and E What have researchers discovered in regards to beta carotene What are the forms functions deficiencies food sources and toxicities of vitamin D What circumstances can effect how much vitamin D the body produces What are the forms functions deficiencies food sources and toxicities of vitamin E Beta carotene is not toxic only the retinol form of vitamin A is It is converted to vitamin A as needed and is difficult to over consume Furthermore people previously believed that a diet rich in beta carotene lowers the occurrence of cancer until the Finnish Smoker study found that after 7 years of administering vitamin A to one of the two patient groups the beta carotene consuming patients had an 18 greater risk of developing cancer than placebo patients In this instance the consumption of the supplement occurred through pills and not natural food which could have made a difference Vitamin D is known scientifically as cholecalciferol animal source or ergocalciferol plant source The body can make vitamin D however most people do not make enough without having to consume some amounts Vitamin D aids in the absorption of calcium thus it is associated with bone formation through mineralization or the depositing of calcium and phosphorous into the bone s collagen protein matrix In children rickets may occur in which the suffer endures a disease where the bone does not mineralize properly causing it to become soft At birth bones are normally soft and harden through mineralization gradually however when they do not strengthen quickly enough legs and ribs may bow under the force of body weight In adults osteomalacia or demineralized bone may occur as a lack in vitamin D causes a lack in calcium The body pulls calcium from the bones weakening them but symptoms are often unnoticed Forty percent of individuals in the US experience a marginal deficiency in this compound There are no good rich sources in the food supply therefore fortified milk and milk products some orange juices and breakfast cereals help Cod liver oil has been used historically in particular for those in Scandinavian countries where 98 of children receive cod liver oil supplement treatment to eliminate rickets Vitamin D is the second most toxic vitamin after vitamin A and only 4 times the RDA is needed to cause over absorption of calcium which allows excess to enter soft tissues It is nearly impossible to consume too much from food naturally In the liver cholesterol is formed into a particular compound that enters the blood so that when the blood nears the surface of the skin and sunlight shines upon it the compound is converted into cholecalciferol The arms legs and face are the best areas for sunlight absorption and conversion and it is