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Judith E. Brown www.cengage.com/nutrition/brown Vitamins and Your Health Unit 20 Prof. Albia Dugger • Miami-Dade College Vitamin Facts • Vitamins • Chemical substances that perform specific functions in the body • Essential nutrients • Two basic types: • Water soluble (B-complex, C) • Fat soluble (D,E,K,A) 14 Known Vitamins Deficiency and Excess • Water soluble vitamins • Only B12 can be stored in the body, all others become deficient in weeks to months if not consumed • Niacin, B6, choline, and C cause ill effects if consumed in excessive amounts Deficiency and Excess • Fat soluble vitamins • Stored in body fat, liver, other parts of the body • Deficiencies take longer to develop • Excess can build up in fat Bogus Vitamins • Some substances sold as vitamins are not vitamins What Do Vitamins Do? • Many vitamins are coenzymes • Coenzymes • Chemical substances that activate specific enzymes that increase the rate of chemical reactions in the body, such as breakdown of energy nutrients, or building body tissues Recommended Intakes • Dietary Reference Intakes (DRIs) • To prevent deficiency and chronic disease • Recommended Dietary Allowances (RDAs) • When data exist for set standards • Adequate Intakes (AIs) • When data are insufficient for set standards Thiamin Thiamin Riboflavin Riboflavin Niacin Niacin Vitamin B6 Vitamin B6 Folate Folate Vitamin B12 Vitamin B12 Biotin Biotin Pantothenic Acid Pantothenic Acid Vitamin C Vitamin C Choline Choline Vitamin A Vitamin A Beta-Carotene Beta-Carotene Vitamin E Vitamin E Vitamin D Vitamin D Vitamin K Vitamin K Avoiding Vitamin Deficiencies • Folate: • 400 mcg/day folic acid before and early during pregnancy reduces neural tube defects • Reduces risk of dementia and certain cancers Key Terms • Dementia • A usually progressive condition (such as Alzheimer’s disease) marked by development of memory impairment and inability to use or comprehend words or to plan and initiate complex behaviors Avoiding Vitamin Deficiencies • Adequate Vitamin A intake: • Prevents some forms of blindness • Reduces severity of measles and other infectious diseases • Used to treat skin for acne, wrinkles, and liver (aging) spots Avoiding Vitamin Deficiencies • Vitamin D (“sunshine vitamin”) • Facilitates calcium utilization • Helps reduce chronic inflammation, which reduces risks of diabetes, cardiovascular disease, multiple sclerosis, certain cancers, and rheumatoid arthritis Key Terms • Chronic inflammation • Low-grade inflammation that lasts weeks or years • Inflammation • First response of the body’s immune system to infection or irritation • Triggers release of substances that promote oxidation and other harmful reactions Recommended Vitamin D Intake • Recommended intake levels for vitamin D are expected to increase • Currently, for adults: 200 IU/day • 800 IU/day is associated with lowered risks • Sources: • Direct sunlight exposure • Fortified foods, supplements Fortified with Vitamin D Vitamin D and Sunlight • Exposing the whole body to direct sunlight for 10-15 min generates 20,000 IU vitamin D • Highest in light-skinned people • Body stops producing vitamin D when adequate amounts have been produced Vitamin D and UV Light • Vitamin D status is lower in areas where sunlight is indirect or weak (e.g. Russia) Antioxidant Vitamins • Antioxidants • Chemical substances that prevent or repair damage to cells caused by exposure to free radicals • Includes beta-carotene, vitamin E, vitamin C • Found in fruits, vegetables, whole grains Key Terms • Free radicals • Chemical substances (usually oxygen or hydrogen) that are missing an electron • Absence of an electron makes the substance reactive and prone to oxidizing nearby atoms or molecules by stealing an electron from them • Damages DNA, cell membranes, and other cell components Key Terms • Beta-carotene is a precursor of vitamin A • Precursor (provitamin) • In nutrition, a nutrient that can be converted into another nutrient Getting Enough Vitamins • Five or more servings a day of a variety of fruits and vegetables can provide adequate amounts of vitamins • Fortified foods can increase vitamin intake substantially Food Sources of Vitamins • Thiamin Food Sources of Vitamins • Riboflavin Food Sources of Vitamins • Niacin Food Sources of Vitamins • Vitamin B6 Food Sources of Vitamins • Folate Food Sources of Vitamins • Vitamin B12 Food Sources of Vitamins • Vitamin C Food Sources of Vitamins • Choline Food Sources of Vitamins • Vitamin A Food Sources of Vitamins • Beta-carotene Food Sources of Vitamins • Vitamin E Food Sources of Vitamins • Vitamin E (cont’d) Food Sources of Vitamins • Vitamin D Preserving Vitamin Content • Vitamin content of foods is affected by food preparation and storage methods • Heat sensitive vitamins (vitamin C, folate) • Water soluble vitamins Vitamins Lost