Transcript Vitamins - CindiLamb.com

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