Term
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Definition
- Vitamins are chemicals in food required in small amounts for normal growth and health
- Adequate intakes protect people against deficiency diseases, prevent chronic diseases
- Every vitamin has range of intake where it functions best
- Intakes below and above range impair health
- 5 or more servings of fruits and vegetables is best strategy to boost vitamin intake |
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Term
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Definition
- Vitamins are chemical substances that have specific metabolic functions
- Primary functions include activating enzymes (serving as co-enzymes)
- Considered essential nutrients because are vital to health
o Cannot be produced by the body in sufficient amounts
- Failure to consume enough vitamins causes specific deficiency diseases
- 13 vitamins have been discovered so far
- Are classified as water-soluble or fat-soluble |
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Term
| Vitamin Classification: Fat Soluble |
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Definition
- Vitamins A, D, E, and K
- Insoluble in water, bile required for digestion
- absorbed like fat into the lymph
- require chylomicrons for transport
- stored in fatty tissues and liver
- potential exists for toxicity
- serve structural and regulatory processes in the body
- deficiency takes longer to develop when dietary intake is low |
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Term
| Vitamin Classification: Water Soluble |
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Definition
- B-vitamins and vitamin C
- primary functions are as co-enzymes
- travel freely in circulation and cells
- easy to absorb and excesses are usually excreted by the kidneys
- lower toxicity than fat-soluble
- small amount stored in body
- Increased need during pregnancy, lactation, growth, fevers, injury, surgery, and alcoholism
- deficiency state more likely
o symptoms may develop in a few weeks or months |
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Term
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Definition
Needed everywhere:
o Eyesight
o Promotes good night vision.
o Epithelial tissues need A to protect integrity.
o A is needed by immune system to fight infections.
o A is needed for bone growth
Sources:
o Animal foods are source of preformed vitamin A.
o ß-Carotene is a precursor of vitamin A
o Brightly colored orange, yellow, and green vegetables/fruits, fortified skim milk. |
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Term
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Definition
Synthesis from precursor sterols by sunlight
Functions:
o Bone growth
o Helps maintain blood calcium
Deficiency Diseases: rickets, osteomalacia (weak bones)
Sources: Fortified milk, sunlight |
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Term
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Definition
- Antioxidant
- Functions: May reduce risk of heart disease.
- Toxicity: Rarely seen.
- Sources: Widespread in plants.
- 60% in American diet comes from nut and seed oils. |
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Term
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Definition
- Involved with blood clotting
- Deficiency Diseases: Possibly uncontrolled bleeding (hemorrhage)
Sources:
o Dark green leafy vegetables (spinach) and liver
o Produced by bacteria in the intestines |
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Term
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Definition
- Functions: Energy metabolism, appetite and nervous system function
- Deficiency Disease: Beriberi |
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Term
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Definition
- Functions: Energy metabolism.
- Toxicity: None reported
- Sources: Milk, Easily destroyed by ultraviolent light. |
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Term
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Definition
Functions:
o Energy metabolism
o Pharmacologic doses, 3-9 grams, may lower cholesterol, LDL cholesterol, increase HDL cholesterol.
- Deficiency Disease: Pellagra
- Sources: high protein foods. |
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Term
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Definition
- Functions: New cell synthesis.
- Deficiency Disease: Megaloblastic anemia
- Sources: fortified grains
- folic acid before and in pregnancy prevents about 2/3 of cases of neural tube defects in newborns
- Neural tube defects are abnormalities of the spinal cord and brain
- Most common type of birth defect
- homocysteine, a risk factor for CVD |
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Term
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Definition
Functions: New cell synthesis
Deficiency Disease:
o Vegans need B12 supplement or use B12 fortified foods
o Others at risk that benefit from supplementation include:
- Sources: animal foods |
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Term
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Definition
Functions: Amino acid synthesis and metabolism
Deficiency Diseases: Seen with chronic alcohol abuse |
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Term
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Definition
| Functions: Energy metabolism |
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Term
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Definition
Functions: Collagen synthesis, antioxidant, enhances iron
absorption
Deficiency Disease: Scurvy.
Sources: Citrus fruits, vegetables and fruits |
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Term
| Who should take multi-vitamin-mineral supplements? |
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Definition
-Pregnant and lactating women: increased need for some nutrients, of note iron & folate
- Women with heavy menstrual bleeding: iron (vitamin C)
- Women of childbearing age/premenopausal women: folate, iron, calcium
- Smokers: B vitamins, vitamin C
- Individuals who abuse alcohol: multivitamin-mineral supplement (Vitamin B1, folate, B6, C)
- Individuals with restricted or limited diets: multivitamin-mineral supplement
- Vegetarians: calcium, iron, zinc, vitamin B2 and B12, vitamin D
- Individuals with limited milk intake and/or sun exposure: calcium, vitamin D
- Older adults (> 70 years of age): calcium, vitamin D, vitamin B6 & B12, zinc
- Individuals with a health condition that affects nutrient utilization or absorption
- Individuals with compromised immune function
- Some infants: Vitamin D (breastfed infants), fluoride, iron |
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Term
| For Vitamin-Mineral Supplements: |
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Definition
- Don’t view as replacements for healthful foods
- Choose a combination that contains < 100% DV for your age and gender
- Avoid “mega”-doses or high potency formulas
- For economy, consider the generic brand and skip the extra ingredients that add to the cost, but offer no proven nutritional benefits
- Check the expiration date
- Take only in recommended doses |
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Term
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Definition
- Vitamins do not provide energy or serve as components of body tissues
- Some vitamins are coenzymes in the conversion of proteins, carbohydrates, and fats into energy
- “Vague” symptoms can precede recognized physical signs of deficiency
- Vitamins are “vital” for health |
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Term
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Definition
- Beta-carotene (a precursor to vitamin A), vitamin E, and vitamin C are antioxidants
- They can prevent or repair damage to cells caused by free radicals
- Antioxidants stabilize oxidized molecules or repair them
Antioxidants
o Chemical substances that prevent or repair damage to cells caused by exposure to free radicals
o Includes beta-carotene, vitamin E, vitamin C
o Found in fruits, vegetables, whole grains |
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Term
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Definition
Beta-carotene is a precursor of vitamin A
Precursor (provitamin)
o In nutrition, a nutrient that can be converted into another nutrient |
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Term
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Definition
- Adequate amounts of vitamins obtained from variety of foods in the Food Guide Pyramid
- Fruits and vegetables are good sources of vitamins
- Fortified foods can increase vitamin intake
- Fortified food consumption may increase intake too much
- Overdoses from fortified foods not currently reported |
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Term
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Definition
- Recommendations for vitamin intakes are represented by Dietary Reference Intakes, or DRIs
- UL determined for most vitamins and indicate levels of intake from foods, fortified foods, and supplements that should not be exceeded |
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