Judith E. Brown

Prof. Albia Dugger • Miami-Dade College

www.cengage.com/nutrition/brown

Vitamins and Your Health

Unit 20

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