Ch 9 Vitamins Learning Objectives 1 List the general functions of vitamins and minerals 2 Identify vitamins that are fat soluble and water soluble 3 Vitamin A a List the functions of vitamin A b Discuss the differences between preformed vitamin A and provitamin A Identify dietary sources of preformed vitamin A and provitamin A d Describe the deficiency and toxicity conditions associated with vitamin A c 11 9 2015 1 Learning Objectives 3 Vitamin D a Discuss the role of vitamin D in calcium metabolism Identify reasons for increased requirements in elderly b List dietary and non dietary sources of vitamin D c d Outline synthesis and activation of vitamin D in body Identify individuals at risk for inadequate body stores e Identify chronic conditions associated with insufficiency f 4 Vitamin E a b List the primary functions of vitamin E Identify population s at greatest risk for vitamin E deficiency c Describe why population s is are at risk Key Terms Rickets Osteomalacia Free radical Antioxidant 11 9 2015 2 Introduction to vitamins Micronutrients Not energy yielding Involved in metabolic processes Assist in providing energy Categories of micronutrients Vitamins Minerals History of vitamins Originally referred to as vitamines Assigned single letters as they were discovered Later discovered that vitamin B was not a single vitamin subscripts assigned Vitamin B1 Vitamin B2 Vitamins categorized into two groups based on solubility 11 9 2015 3 Water soluble and fat soluble vitamins Fat Soluble vs water Soluble Vitamins Fat Soluble Water Soluble Storage in body Storage in body longer period of time larger amounts in liver and fat cells short period of time not generally stored in large quantities 11 9 2015 4 Vitamin A Occurs in three different chemical forms Most active form of vitamin A stored in the liver 1 Retinol 2 Retinal 3 Retinoic acid Functions integrity of epithelial cells bone growth reproduction cell membrane stability gene regulation vision immune function Recommended Intakes for Vitamin A RDA 900 g RAE per day for men 700 g RAE per day for women Increased needs for Women who are pregnant and breastfeeding May also be listed in International Units IU 11 9 2015 5 Food Sources of Vitamin A 1 Preformed vitamin A ready to use 2 Provitamin A Ex beta carotene Green leafy vegetables Orange and red produce Apricots cantaloupe carrots sweet potatoes and pumpkins Functions of vitamin A 1 Crucial to normal vision Early stages of deficiency 2 Maintenance of healthy cornea tissue outer layer of eye Short term vitamin A deficiency Cornea becomes dry and damaged Long term vitamin A deficiency 11 9 2015 6 Functions of vitamin A 3 Disease resistance particularly for children Production of white blood cells 4 Integrity of epithelial cells Found in the skin lungs and lining the gastrointestinal tract 5 The process by which specialized cells develop that are capable of performing specific functions Functions of vitamin A 6 Gene regulation Role in turning genes on and off Indirect role in the regulation of metabolism 7 Bone metabolism Stimulates the bone cells that break down the inner part of bone Can lead to poor growth in children 11 9 2015 7 Vitamin A Toxicity Vitamin A stored in fat tissue and liver Stored in the body for a long time Symptoms of vitamin A toxicity include Should you take beta carotene supplement Health professionals do not recommend beta carotene supplementation for the general public 11 9 2015 8 Vitamin D Another name for vitamin D is cholecalciferol classified as vitamin hormone and steroid Functions of Vitamin D Regulation of calcium metabolism stimulates cells of small intestine to produce calbindin a calcium binding protein stimulates kidneys to conserve calcium stimulates calcium release from bone to cid 207 blood levels Recommended Intakes of Vitamin D Food and Nutrition Board of Institute of Medicine recommends 400 IU 10 g per day infants AI 600 IU 15 g per day ages 1 to 70 yrs RDA The requirement cid 207 as we age 800 IU 20 g per day for adults age 70 RDA Why 11 9 2015 9 Food Sources for Vitamin D Very few foods are naturally concentrated in vitamin D Cod liver oil Mushrooms exposed to UV light relatively small amount Fortified foods provide majority of dietary vitamin D Cheese and yogurt are not often fortified with vitamin D Making Your Own Vitamin D Human body makes vitamin D with adequate exposure to sunlight through a series of steps Eventually makes it way to the kidneys cereals juices 11 9 2015 10 11 9 2015 Synthesis of vitamin D in the body Making Your Own Vitamin D Factors that influence vitamin D synthesis Skin color Age 11 Vitamin D Deficiency and Bone Effects Children a disease characterized by softening and deformity of long bone inability to deposit calcium in newly formed bone Malformation of skull rib cage and ends of long bones Adults softening of bone caused by decalcification Vitamin D Deficiency and Bone Effects 11 9 2015 12 Vitamin D Toxicity Toxicity is not common Occurs from overuse of supplements Symptoms of vitamin D toxicity Nausea vomiting and diarrhea May also lead to the calcification of soft tissues Food fortification with vitamin D is strictly regulated To Supplement or Not High rates of vit D insufficiency in U S 90 of ethnic populations with dark skin 75 of caucasian population Possible link between vit D insufficiency and chronic disease 11 9 2015 13 Vitamin E Fat soluble vitamin Primarily found in cell membrane Not a single compound but is a group of compounds called tocopherols four different types of tocopherols alpha beta gamma and delta Functions of Vitamin E 1 Neutralize free radicals that can damage cell membranes DNA and proteins 2 Enhances immune function 3 Required for nerve cell development In past use of vit E supplements recommended to protect against cancer and CVD 11 9 2015 14 Vitamin E and Free Radicals As an antioxidant vitamin E fights against Attack other molecules with electrons Initiates a chain reaction Damages cell membranes proteins enzymes and DNA Free radicals from multiple sources damage cells 11 9 2015 15 Recommended Intakes for Vitamin E 15 mg per day for adults RDA Tolerable Upper Intake Level UL is 1 000 mg per day for adults UL may be lower for some populations Increased incidence of brain hemorrhage among smokers who take vitamin E supplements Vitamin E Deficiency Vitamin E deficiency is rare Most likely to occur in Condition resulting from vitamin E deficiency due to red blood cell fragility and