HES 2823 1st Edition Lecture 18 Outline of Last Lecture I Fat Soluble Vitamins continued A Vitamin A continued 1 Deficiency 2 Food Source 3 Toxicity Outline of Current Lecture I Fat Soluble Vitamins continued A Vitamin A continued 1 Toxicity continued B Vitamin D 1 Function 2 Deficiency 3 Food Sources 4 Toxicity C Vitamin E 1 Function 2 Deficiency Current Lecture I Fat Soluble Vitamins continued A Vitamin A continued 1 Toxicity continued a Acute continued i Polar bear liver has enough vitamin A to kill a human consuming it b Chronic i 4x RDA over a time period ii When over consumed vitamin A enters the blood and acts like soap and dissolves membranes attacking the liver first iii Beta carotene is benign not toxic only the retinol form of vitamin A is i It is converted to vitamin A as needed ii Difficult to over consume These 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 iii Believed that a diet rich in beta carotene lowers the occurrence of cancer iv Finnish Smoker Study 1 7 year study with two groups of smokers given either vitamin A or a placebo 2 Beta carotene consuming patients had 18 greater risk of cancer than placebo patients 3 The consumption was through pills and not natural food B Vitamin D 1 Cholecalciferol animal source 2 Ergocalciferol plant source 3 The body can make vitamin D however most people cannot make enough on their own a In the liver cholesterol is formed into a particular compound that then enters the blood so that when the blood passes beneath the skin and sunlight shines upon it it is converted into cholecalciferol b The arms legs and face are the best areas for sunlight absorption and conversion c Recommendation 15 minutes of sensible sun exposure produces enough vitamin D to lower dietary needs but not eliminate them d One s geographical location regarding the equator can effect the required dietary amounts e Darker skin colors require higher amounts of dietary vitamin D f Remaining indoors wearing protective clothing and applying sunscreen heighten dietary requirements as well 4 Function a Aids in the absorption of calcium and thus bone formation i Mineralization the depositing of calcium and phosphorus into bone 5 Deficiency a In children rickets a disease in which bone does not mineralize properly causing it to become soft i At birth this is normal as bone takes time to mineralize ii When this does not occur due to deficiency legs bow under the force of body weight and pigeon ribs occur under the pressure of lungs against the rib cage as the ribs begin to point outward iii Swaddling clothes were originally used to prevent deformity in infants iv It was thought that rickets had been eliminated in the US 20 30 years ago but this untrue as at risk dark skinned infants still experience this due to less sun absorption b In adults osteomalacia demineralized bone i The lack of vitamin D causes a lack of calcium ii The body pulls calcium from the bones weakening them iii No symptoms seen or felt typically iv Gastric bypass malabsorption and malnutrition call for much examination in those patients and 10 15 years ago these tests found vitamin D deficiencies in 85 of those tested i The obese are at a greater risk but 40 of individuals have a marginal deficiency ii Marginal deficiency is common in the US increasing cancer and heart disease risks 6 Food Sources a No good rich source in food supply b Fortified milk also milk products such as yogurt and cheese some orange juices are fortified fortified breakfast cereals c Cod liver oil historically i Scandinavian countries rickets eliminated due to cod liver oil routine supplements in 98 of children 7 Toxicity a Second most toxic vitamin after vitamin A b 4x RDA required to cause problems c Over absorption of calcium occurs causing the excess to be dumped into soft tissue like the kidneys aorta and muscles d Cannot consume too much vitamin D from food naturally C Vitamin E 1 Tocopheral chemical name but alpha tocopheryl acetate signifies is presence on pill bottles 2 Function a Antioxidant prevents oxidation destruction of important biochemical i In the cell enzymes are converted into free radicals which are very reactive compounds that need protection 3 Deficiency a Hemolytic anemia fatigue because of lack of oxygen within a cell i Red blood cells rupture because the lipids in the cell membrane are oxidized ii Uncommon but the at risk group is premature infants