Chapter 7 Vitamins

Question 0

Essential nutrients to be provided by diet

Answer 0

Vitamin D synthesized by the body but still considered vitamin.

Question 1

Vitamins

Answer 1

• -Organic molecules needed in very small amounts for cellular metabolism.
• -Perform specific metabolic functions
• -Vitamins except D are not synthesized; dietary intake. D created by body

Question 2

Dietary reference intakes (DrIs)

Answer 2

• -recommended dietary allowance(RDA)
• -adequate intake (AI)
• -tolerable upper intake level (UL)

Question 3

Vitamin categories

Answer 3

Water soluble

Fat soluble

Question 4

Solubility affects

Answer 4

Water sol. absorbed small intestine and then pass into bloodstream
Fat sol. Bile

Question 5

Water-soluble

Answer 5

• B complex vit. (Thiamine, riboflavin, niacin, pyridoxine, folate, vit. B12, biotin, pantothenic acid) choline, vit C
• minimal storage
• deficiencies develop more quickly
• usually low risk of toxicity

Question 6

Fat-soluble

Answer 6

A,D,E,K

• excess stored in body
• deficiencies longer to develop
• greater risk of toxicity

Question 7

Food sources

Answer 7

Vitamins in almost all foods
Synthetic vitamins (same function)

Question 8

Synthetic vitamin

Answer 8

Best to consume vitamins from food sources
May lack other benefits found in foods
Photochemicals

Question 9

Phytochemicals

Answer 9

Nonnutritive substances in plant-based foods that appear to have disease-fighting properties.

Question 10

Thiamine (B1)

Answer 10

Coenzyme in energy metabolism
*role in nerve functioning related to muscle actions
Recommended intake and sources
* sources- lean pork, whole/enriched grains and flours, legumes, seeds and nuts

Question 11

Thiamine cont’d

Answer 11

Deficiency: beriberi: ataxia, tachycardia

• -marginal: psychologic disturbances, head ache, fatigue, irritability
• -wet vs dry beriberi
• -wernicke-korsakoff syndrome
• -risk: alcoholism, renal dialysis, anorexia, gastrectomy
• -toxicity: nontoxic

Question 12

Ataxia

Answer 12

Muscle weakness and loss if coordination

Question 13

Tachycardia

Answer 13

Rapid beating of heart

Question 14

Wet beriberi

Answer 14

Manifests w/ edema, affecting cardiac functioning by weakening the heart muscle and vascular system.

Question 15

Dry beriberi

Answer 15

Nervous system, producing paralysis and extreme muscle wasting.

Question 16

Wernicke-Korsakoff syndrome

Answer 16

Cerebral form of beriberi

Most common disorder of CNS as a neuropsychiatric affect of chronic excessive alcohol intake on nutritional status.

Question 17

Riboflavin (B2)

Answer 17

Coenzyme in energy release
Recommended intake/sources
*RDA 1.3 mg men; 1.1 women
*need related to total kcal intake, energy needs, body size, metabolic/growth rate
*sources: milk, enriched grains/cereals, whole grains, veggies, dairy, meats, fish, poultry, eggs
*very light-sensitive: kiss increases on exposure to artificial and natural light; list in cooking water.

Question 18

Riboflavin cont’d

Answer 18

Deficiency: ariboflavinosis
* cheilosis, glossitis, seborrheic dermatitis
Toxicity: non toxic

Question 19

Ariboflavinosis

Answer 19

Name for a group of symptoms associate w/ riboflavin deficiency.
Lips become swollen and cracks in corners (cheilosis)
Tongue becomes inflamed, swollen, and purplish red (glossitis)

Question 20

Seborrheic dermatitis

Answer 20

Skin condition characterized by greasy scales, may occur in regions of ears, nose, and mouth.

Question 21

Niacin(B3)

Answer 21

Nicotinic acid and niacinamide

*coenzyme for many enzymes, especially energy metabolism; critical for glycolysis and tricarboxylic acid (TCA) cycle

Question 22

Niacin contd

Answer 22

RDA: 16 mg NE men 14 women
*RDA stated as niacin equivalent (NE)
*a.acid and tryptophan precursor of niacin
*60 mg tryptophan converts 1mg niacin
Diets adequate in protein=adequate in niacin
Sources: protein; meats, poultry, fish, legumes, enriched cereals, milk, coffee, tea.

Question 23

Niacin contd

Answer 23

Pellagra
*3 D’s
1. Diarrhea: GI tract damage alters digestion, absorption, excretion, leading to glossitis, vomiting, and diarrhea.
2. Dermatitis: symmetric scaly rash occurs only on skin exposed to sun
3. Dementia: severe deficiencies, confusion, anxiety, insomnia, paranoia develop
At risk: excessive alcohol consumption; malabsorption

Question 24

Niacin contd

Answer 24

Toxicity: causes vasodilation and flushing effect

• UL 35 mg NE per day
• pharmacological doses: 3-9g, may lower total cholesterol, decrease LDL and increase HDL
  - -require monitoring to prevent liver damage, gout, and arthritis

Question 25

Pyridoxine (B6)

Answer 25

Pyridoxine, pyridoxal and pyridoxamine

• -pyridoxal phosphate (PLP) acts as coenzyme in metab. Of aacids and proteins
  
  • necessary to hemoglobin synth
  • req. for conversion of tryptophan to niacin
  • coenzyme for fatty acid and CHO metab
  • supplements of B6, folate, and B12 may reduce risk of CAD