Midterm #3—Study Guide
1. What do water soluble vitamins act as?
a. Coenzymes
i. Protein + coenzyme = active enzyme
2. What are B-Vitamins?
a. Thiamin
b. Riboflavin
c. Niacin
d. Pyridoxine – B6
e. Folic acid
f. Panthothenic acid (coenzyme A) & biotin (carb, fat, and amino acid metabolism)
3. What do B-vitamin deficiencies affect?
a. Brain and nervous system
b. Skin
c. GI tract
d. *alcohol abuse poses the greatest risk for such deficiencies
4. What is the function of Thiamin?
a. Carbohudrate and metabolism
b. Make ribose to form RNA
c. Maintenance of normal appetite and in normal muscle tone in GI tract
5. What are the sources of thiamin?
a. Richest
i. Lean pork
b. High
i. Whole grains, enriched cereals
6. What happens with thiamin deficiency?
a. Beriberi, I can’t I can’t (Sinhala language)
b. Deficiency became wifespread with advent of polished rice. Was thought to be
an infectious disease
7. What are the recommendations for thiamin?
a. Depends on carb intake
b. Beriberi is rare in the US
c. In time of growth, pregnancy, lactation or with alcoholic, marginal deficiencies
are sometimes observed
8. What is the function of Riboflavin—B2?
a. Release of carb energy
b. Breakdown of fatty acids and amino acids
9. What are the sources of riboflavin?
a. Light sensitivity
b. Riches
i. Milk and dairy
1. High calcium foods
10. What are the functions of Niacin –b3?
a. Release energy
i. From carbs, proteins, fats
ii. Component of two coenzymes involved in energy metabolism (NAD and
NADP)
b. Make proteins, DNA, RNA
11. What are the sources?
a. Rich
i. Meat liver, peanut butter
ii. Corn is a poor source
12. What about deficiency?
a. Pellagra – rough skin
b. 4 Ds
i. dementia
ii. diarrhea
iii. dermatitis
iv. death
13. what about toxicity with niacin?
a. From mega doses (5-10x RDA) 100mg
b. Especially nictonic acid
c. Upper level: 35 mg
14. What are the symptoms?
a. Flushing “niacin rush”
b. Eventual liver damage
15. What about the enrichment?
a. Refining of grains removes b vitamins and has resulted in historical deficiencies
b. The US require that such grains contain nutrients added back to the level that
would be found in whole grain
c. This has also been used as a vehicle to add other nutrients that were not
removed during processing
16. What about enrichment?
a. Required
i. Thiamin
ii. Riboflavin
iii. Niacin
iv. Iron
v. Folic acid
b. Optional
i. Calcium
ii. Vitamin d
17. What about b6 (pyridoxine) functions?
a. Metabolism of amino acids
b. Conversion of glycogen to glucose
c. Deficiency = rare
d. Increased need for b6 in pregnancy
e. Alcoholism poses a risk for deficiency
18. What are sources of b6?
a. Meats, potatoes, bananas
b. Upper level = 100mg
19. What about toxicity?
a. >200mg/day: toxic in a few weeks
i. numb hands and feet
ii. nerve damage
20. What about folate (folic acid)
a. The synthetic form – folic acid – the most potent form
21. What is the function of folic acid?
a. Regeneration of cells
i. Synthesis of DNA
22. What about deficiency?
a. Red blood cell formation
i. Megabloastic anemia (large immature red cells)
23. What happens with folate deficiency?
a. Neural tube defects – opening in the spinal cord of the brain
b. Occurs in 3rd week of pregnancy
c. Form maternal folate deficiency and genetic defect in folate metabolism
24. What about pregnancy?
a. Women of reproductive age who are considering becoming pregnant or who
might become pregnant should be sure that they have an adequate intake of
folic acid
b. The crucial stage where a folic acid deficiency affects a pregnant is very early in
the pregnancy
25. What are the sources of folate?
a. Green, leafy, veggies
b. Orange juic e
c. Grain products that are now fortified with folic acid
26. What is the function of b-12?
a. Similar to to folate
b. RBC formation
c. Unique function
i. Maintains nerve insulation
1. Myelin sheath
27. What about b12 absorption?
a. Requires intrinsic factor?
i. Secreted by stomach
ii. Binds to b12
iii. Complex absorbed in small intestine
28. What are the sources of b12?
a. Made by bacteria, fungi, algae
b. Animal products
i. Meats, organ meat
ii. Seafood
iii. Eggs
iv. Milk
29. What about deficiency?
a. At risk?
i. Vegans- no animal products
ii. Eldery
1. Poor absorption
a. Consumer crystalline B12 over age 50
30. What is megalbolastic anemia?
a. First symptom
b. Excess folic acid can mask this symptom
31. What are functions of Vitamin c?
a. Absorbic acid
b. Formation of collagen
c. Connective tissue
d. Wound healing
e. Increasing in iron absorption
32. What about deficiency?
a. Scurvy
i. Symptoms:
1. Poorly formed collagen
2. Abnormal bones and joint pain
3. Weak blood vessels
a. Gums bleed, small hemorrhages, bruising
b. At risk:
i. Alcoholic, poor people
33. What are the sources of vitamin c?
a. Citrus fruits
b. Potatoes
c. Green peppers
d. Broccoli
e. Liver
34. Is water essential?
a. Yes, we can’t make enough to survive
35. What is water?
a. 50-70% of the body
b. muscle contains 73% water
c. fat contains around 20% water
d. intracellular water?
i. Water within the cell
e. Extracellular water?
i. Outside the cells
36. Why are we keeping water in our bodies?
a. Water shifts freely in and out of cells
b. Controlled by the electrolyte concentration
c. Intracellular water colume depends on intracellular potassium and phosphate
concentrations
d. Extracellular water volume depends on extracellular sodium and chloride
concentration
37. What are the functions of water?
a. Body temp. regulation
i. Water absorbs excess heat
ii. Body secretes fluid via perspiration
iii. Skin is colled as perspiration evaporates
b. Removal of waste
i. Urine
c. Joint lubricants, salvia
38. Are you drinking enough?
a. Men – 13 cups per day
b. Women – 9 cups. Day
39. What is the thirst mechanism?
a. Not reliable
b. Should drink water before you are thirsty
c. Thirst single is not triggered until person loses 1-2% of body weight in fluid
d. Concerns for infants, older adults, and athletes
i. Athletes need to monitor their fluid status
ii. Weigh themselves before and after training
iii. Goal is to consume 3 cups for every lost pound
e. Illness
i. Vomiting
ii. Diarrhea
iii. Fever
40. How to conserve water?
a. Antidiuretic hormone
i. Forces the kidney to conserve water (reduce urine flow)
ii. Reabsorb water into the body
b. Aldosterone
i. Signals the kidney to retain sodium
41. What are minerals?
a. Inorganic- no carbons
b. Some minerals are essential for metabolic function
c. May serve as cofactors or structural components
d. Essential minerals are classified as major or trace
42. Absorption of minerals?
a. Not all ingested minerals can be absorbed well
b. Presence of dietary fiber
c. Minerals from animal products are better absorbed
d. Soil content of mineral
e. Mineral/mineral competition
f. Presence of vitamins
43. What about toxicity?
a. Trace minerals are more toxic than major minerals
b. Result of supplementation misuse
44. Sodium?
a. Table salt (NaCl)
i. 40% sodium, 60% chloride
b. 95% of ingested sodium is absorbed
c. positive ion (Cation) in extracellular fluid
d. water balance
e. muscle concentration
f. conduction of nerve impulses
45. what about deficiency in sodium?
a. Very rare
b. Persistent vomiting/diarrehea
c. Excessive perspiration (losing 2-3%) of body weight
d. Muscle cramp, nausea, vomiting, dizziness, shock, coma
e. Normal kidney will respond by conserving sodium
46. What are the food sources of sodium?
a. 1/3-1/2 of intake is added to food by individual
b. ½-2/3 is added by food manufacturers
c. processed foods contribute to much of the sodium
d. lower salt products available
47. what are the sodium needs?
a. Body only needs 100mg/day
b. Daily value: 2400mg/day
c. Typical intake: 4000-7000mg/day
48. What about salt sensitive people?
a. 10-15% of adults
b. high sodium intake leads to high blood pressure
c. recommend 2-3 gm sodium per day
d. check your blood pressure regularly
49. What about choloride?
a. Negative ion (anion) for the extracellular fluid
b. Component of hydrochloric acid nerve function (HCL)
c. Much is obtained from salt consumption
50. What is hypertension?
a. High blood pressure
51. Why control blood pressure?
a. Silent killer
b. To prevent:
i. Cardiovascular disease, kidney disease, stroke, decline in brain functions
c. 500k deaths/yr
d. African-Americans most at risk
52. What are the causes of hypertension?
a. Aging
b. Atherosclerosis
c. Obesity
d. Inactivity
e. Excess alcohol
f. Sodium sensitive
53. Sodium and blood pressure?
a. Unclear if it is sodium or chloride that is responsible
b. Increases blood pressure with intake (salt-sensitive)
c. Consume no more than 2400 mg/day
d. Fluid retention leads to increase blood volume
54. What is the dash diet?
a. Low fat
b. High fruits and veggies/grains
c. Dariy foods
d. Calcium, potassium, magnesium
e. Good for prevention of many chronic diseases
55. What about medication and HTN
a. Diuretics
i. Reduce blood volume
ii. Increase urine output
b. Slows heart rate
i. Relaxation of the blood vessels
56. Potassium?
a. Positive cation in the intracellular field
b. Functions in fluid balance and nerve impulse transmission
c. Associated with lowering blood pressure
d. 90% of potassium consumed is absorbed
57. what are the food sources and need for potassium?
a. Widely available
b. Minimum requirement is 2000mg/day
c. 3500 mg/day = daily value
58. What about deficiency in potassium?
a. Rare
b. Use of diuretics
c. Alcoholics
d. Anorexia
e. Bulimia
f. Loss of appetite, muscle cramp, constipation, irregular heartbeat