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Nutrition Source � Salt and Sodium
1. How can we recognize people who are at high risk of health problems from salt?

"The high-risk group includes people who are over age 40
2. List the types of foods that supply most of the salt in the Western diet.

"Most of our salt comes from prepared foods
3. What are the reasons why the food industry favors adding extra salt to its products?

#N/A
4. Compare the amount of sodium in primitive diets to the amount in modern diets.

"The Yanomamo people
5. How does increasing intake of sodium place stress on the heart and blood vessels?

"In most people
6. How does the ratio between sodium and potassium content differ between processed food diets and unprocessed food diets?

"Today
7. What is the term for a study that compares the diet and health status of two or more countries to each other?

ecological studies
"8. According to meta-analyses

which vascular disease is most affected by high salt intake?"
9. Which type of cancer has been linked with high salt intake?

"in general
10. How does salt affect calcium balance and bone density?

"The more salt you take in
11. Why has the relationship between salt intake and blood pressure been controversial?

?
12. What are the flaws in the argument that only individuals with hypertension need to limit salt in order to reduce their risk of vascular disease?

"The idea that only some people are �salt sensitive� is a myth. Our bodies are exquisitely sensitive to salt
13. Which individuals should limit sodium intake to 1500 mg per day?

"People who have high blood pressure or are likely to develop high blood pressure should consume no more than 1
14. Describe some strategies for reducing salt intake while still enjoying food.

we can replace salt with other delicious seasonings.
15. Which people should be cautious about using potassium-containing salt substitutes?

"extra potassium can be dangerous for people who have trouble flushing out any excess or who are taking medications that can increase potassium levels in the bloodstream. This includes people with diabetes or kidney disease
Nutrition Source � Beverages
16. Why is water probably the best choice for a regular beverage?

"Water provides everything the body needs�pure H2O�to restore fluids lost through metabolism
17. What are the pros and cons of using coffee or tea as regular beverages?

"These are calorie-free
18. What nutrients do milk and milk substitutes supply that most other beverages do not?

"calcium and vitamin D
19. Name the artificial sweeteners approved for use in foods and beverages.

"aspartame (Equal�
"
20. High consumption of soft drinks appear to increase risk of which health problems?

"Obestiy
"21. According to emerging research

why might artificial sweeteners not be helpful for losing or maintaining weight?"
22. Why might soft drinks have more impact on weight gain than solid foods containing similar amounts of calories?

"Fluids may not be as satiating as solid foods. That means they don't provide the same feeling of fullness or satisfaction that solid foods do
"
23. What are the pros and cons of consuming vegetable or fruit juices in the diet?

"One-hundred-percent fruit juice has most of the nutrients of the fruit itself
24. Why can alcohol consumption be viewed as a �double-edged� sword?

#N/A
25. What is the definition of moderate alcohol consumption?

"Moderate drinking sits at the point at which the health benefits of alcohol clearly outweigh the risks. The latest consensus places this point at no more than one to two drinks per day for men
26. Describe the known and suspected health benefits of alcohol consumption.

"heart attack
27. What are the suspected mechanisms behind the health benefits of alcohol consumption?

"Moderate amounts of alcohol raise levels of high-density lipoprotein (HDL
28. Describe the known and suspected health risks of alcohol consumption.

#N/A
29. How can some of the health risks of alcohol consumption be moderated by attention to other nutrients?

"Adequate daily intake of folate
"30. Give examples of people who should probably avoid alcohol

and of people who should be encouraged to maintain a moderate intake if they desire?"
"
31. What is the �French Paradox� and what is the current status of this controversy?

"The comparatively low rate of heart disease in France despite a diet that includes plenty of butter and cheese has come to be known as the French paradox. Some experts have suggested that red wine makes the difference
Course Notes � Sodium Chloride
32. How are sodium and chloride different from potassium in terms of their location in tissues? What is the physiological significance of this difference?

"Sodium and Chloride are extracellular fluid and Potassium is intracellular fluid. they maintain membrane potential critical for nerve impulse transmission
33. For what physiological functions is tight control of cell membrane potential critical?

Blood sodium levels are under tight control and Sodium plays a role in water absorption in small intestine.
"34. What types of athletes

athletes� drinking habits
35. How do the latest recommendations for sodium and salt intake compare with average intakes in the US?

" average sodium intake 3.1-4.7 grams/d ?
36. What is the source of the majority of salt found in the US diet?

75% comes from salt added in processing and manufacturing food!
37. List some commonly eaten foods that are high in salt.

"Processed meat
38. How does sea salt compare to regular table salt?

Not a lot of difference since sea salt is 80% sodium chloride and 15% moisture and very little other minerals.
39. What aspects of diets in Asia may increase the risk of gastric cancer in those countries?

"Could be due to carcinogens in salted Asian foods
"40. What is the relationship between high salt intake

bone loss
"
41. The risk of which health problems may be significantly lowered by even small reductions in blood pressure?

"low sodium diets can lower blood pressure and
42. Which individuals are most likely to be salt-sensitive in terms of their blood pressure?

"salt-sensitivity increases with age and many age-related conditions
43. Why should the majority of people limit salt in their diet?

"With the lifetime risk of developing hypertension being more than 90% in an average lifespan
Course Notes � Potassium and Fluids and Beverages
44. How are sodium and chloride different from potassium in terms of their location in tissues? What is the physiological significance of this difference?

"Potassium Maintains
45. What conditions and medical treatments can lead to hypokalemia?

"Diuresis
46. How do the AI recommendations for potassium compare to the recommendations for sodium?

Potassium for adults should be 4.7 g/day and sodium was 1.5 g/day.
47. Where in the diet does most potassium come from?

"Friuts and vegetables like; banannas
48. Which high-potassium foods are typically eaten without added salt?

Fruits????
49. Are multivitamin-mineral supplements in the US good sources of potassium?

OTC supplements are limited to a trivial 100 mg due to concerns about side effects of higher potencies. C. Prescription potassium supplements with high potencies come with several warnings.
50. How does the ratio of sodium chloride and potassium in the modern diet compare to that in the diet of primitive cultures?

Western diet is 3:1 Na:K; primitive diets contain more potassium than sodium
51. Risk of which cardiovascular diseases appears to be reduced by increased dietary potassium intake?

"A higher sodium to potassium excretion ratio is associated with increased risk of subsequent CVD
52. What theory attempts to explain why increased dietary potassium intake reduces bone loss and risk of kidney stones?

"Bone loss- potassium will reverse the effects of sodium (Recent research suggests that a high-salt diet increases the rate of bone resorption in postmenopausal women over a 4-week period
53. What is the relationship between potassium intake and blood pressure?

DASH diet successfully lowers BP. DASH diet is full of minerals like potassium and it lowers blood pressure with or without salt restrictions.
54. What has the DASH diet research shown regarding the contribution of potassium-containing foods to reducing the risk of several chronic diseases?

DASH diet successfully lowers BP (and improves many other risk factors).
55. What types and amounts of potassium supplements may have useful clinical benefits?

"1. Moderate effect on blood pressure using 2300-3900 mg/d. 2. Beneficial effects on bone mass
56. What conditions and medical treatments can lead to hyperkalemia? What are the best ways to screen patients in order to avoid problems associated with using potassium supplements?

Hyperkalemia is most likely with kidney dysfunction or use of potassium-sparing drugs. 2. It is best to check serum potassium levels in older and diabetic patients before recommending large increases in potassium intake.
57. Distinguish between blood pressure medications that can cause hypokalemia and those that can cause hyperkalemia.
58. Why might the recommendation to drink eight glasses of water per day be called controversial?

"Eight glasses� or 2 liters daily originated as a calculation of total daily body water losses
59. What are the benefits of sports drinks over water for endurance athletes?

"While electrolyte replacement is not often needed during exercise lasting less than four hours
Linus Pauling Institute � Tea
60. What potentially-beneficial class of compounds are found in tea made from Camellia sinensis?

flavonoids
61. What happens to natural catechins in fresh tea leaves when they are fermented? Which types of teas are most highly fermented?

"Fresh tea leaves are rich in flavonoids known as catechins (figure 1). Tea leaves also contain polyphenol oxidase enzymes in separate compartments from catechins. When tea leaves are intentionally broken or rolled during processing
62. What factors determine the caffeine content of brewed tea?

"All teas contain caffeine
63. Which element is present in substantial amounts in tea?

"Tea plants accumulate fluoride in their leaves. In general
64. Discuss the evidence for a role of tea consumption in the prevention of cardiovascular disease.

"Thus
"
65. Discuss the evidence for a role of tea consumption in the prevention of cancer.

"More recently
66. Discuss the evidence for a role of tea consumption in the prevention of osteoporosis.

Further study is required to determine whether tea consumption affects the development of osteoporosis or the risk of osteoporotic fracture in a meaningful way.
67. Which mineral may be poorly absorbed when consumed at the same time as tea?

"Flavonoids in tea can bind nonheme iron
Linus Pauling Institute � Coffee
68. Which family of compounds found in coffee may have significant antioxidant activity?

"Although chlorogenic acid and caffeic acid have antioxidant activity in vitro (3)
69. How does caffeine exert its biological effects?

"caffeine appears to exert most of its biological effects through antagonism of the A1 and A2A subtypes of the adenosine receptor (5). Adenosine is an endogenous compound that modulates the response of neurons to neurotransmitters. Adenosine has mostly inhibitory effects in the central nervous system
70. Which compounds found in coffee may have effects on blood cholesterol? Which types of brewing results in the highest amounts of these compounds in a cup of coffee?

"Some cafestol and kahweol are extracted from ground coffee during brewing
71. The risks of which health problems appear to be lower in people who consume the most coffee?

#N/A
72. Which health problems may be more severe in people who consume the most coffee?

#N/A
73. What are the symptoms of caffeine excess?

"Most adverse effects attributed to coffee consumption are related to caffeine. Adverse reactions to caffeine may include tachycardia (rapid heart rate)
74. What are the symptoms of caffeine withdrawal?

#N/A
75. How important is coffee and caffeine consumption among the multifactorial influences on osteoporosis risk?

"the impact of coffee or caffeine consumption on the risk of osteoporosis is not clear. However
76. Which mineral may be poorly absorbed when consumed at the same time as coffee?

Iron.
"Nutrition Source � Calcium

Vitamin D"
1. What are some biological functions of calcium besides building and maintaining bone?

"can lower the risk of osteoporosis and colon cancer. Calcium is a mineral that the body needs for numerous functions
"
2. At about what age does bone remodeling typically change from net gain to net loss of bone?

"In healthy individuals who get enough calcium and physical activity
3. What factors contribute to bone loss later in life?

"The loss of bone with aging is the result of several factors
4. Why must preventing osteoporosis begin early in life?

"Preventing osteoporosis depends on two things: making the strongest
5. What are the limitations of maximum-calcium-retention studies for determining calcium requirements?

But the maximum-calcium-retention studies are short term and therefore have important limitations. To detect how the body adapts to different calcium intakes over a long period of time�and to get the big picture of overall bone strength�requires studies of longer duration.
6. What other nutrition and lifestyle factors should be combined with adequate calcium intake to most effectively prevent osteoporosis?

"there was some suggestion that calcium supplements taken without vitamin D might even increase the risk of hip fractures. Vitamin K
7. What components of dairy products may be health hazards for some people? How can the effects of some of them be minimized for people who want to use milk products?

"Lactose intolerant; One alternative for those who are lactose intolerant but who still enjoy consuming dairy products is to take a pill containing enzymes that digest milk sugar along with the dairy product
"
8. Which populations are most likely to be lactose intolerant?

"90 percent of Asians
9. What possible health risks have been identified for high consumption of cow�s milk products?

"Lactose intolerance
10. What potential health benefits other than preventing bone loss have been identified for calcium and dairy products?

#N/A
11. What foods other than milk are good calcium sources?

"Calcium can also be found in dark green
12. What plant component limits calcium availability from some foods?

"Calcium is also found in spinach and chard
13. What countries worldwide and what parts of the United States do not likely experience enough sun exposure to provide adequate vitamin D?

"If you live north of the line connecting San Francisco to Philadelphia and Athens to Beijing
14. List all of the risk factors that predict vitamin D insufficiency or deficiency.

"There are a number of factors that increase the risk of vitamin D deficiency
15. What is the best way to assess whether someone has adequate vitamin D status?

Blood test.
16. The risk for which health problems is higher in people with low vitamin D status?

"Vitamin D deficiency could thus lead to several potential problems
17. Why is it difficult to get enough vitamin D from the diet?

"Fatty fish is the only good natural source of vitamin D. A 3.5 oz serving of cooked salmon
18. Why is the possibility that vitamin D may help prevent or treat non-skeletal diseases still considered an unanswered question?

"Vitamin D's role in many of these diseases has not been definitively proven through a randomized trial. Nonetheless
19. What is the likely reason that some fracture prevention studies did not find vitamin D supplements helpful?

"trials that provided only 400 IU per day did not show this benefit. It is reasonable to postulate that more than 800 IU per day would provide even more benefit
"20. How can we distinguish between the two principal forms of vitamin D

one of which may be more bioavailable?"
21. How might vitamin D prevent elderly people from falling?

"Vitamin D may also help increase muscle strength
22. How might vitamin D protect the cardiovascular system?

#N/A
23. For which cancers is the evidence strongest that vitamin D might reduce their risk?

colon cancer
24. Describe the evidence for the role of vitamin D in autoimmune disease.

those with the highest vitamin D blood levels had a 62 percent lower risk of developing MS than those with the lowest vitamin D levels. Children who regularly received vitamin D supplements during infancy had a nearly 90 percent lower risk of developing type 1 diabetes than those who did not receive supplements.
25. Describe the evidence for the role of vitamin D in infectious disease.

"The active form of vitamin D tempers the damaging inflammatory response of some white blood cells
"
Course Notes � Vitamin D
26. What is the biochemical name for natural and for synthetic vitamin D?

Natural- Vitamin D3 � Cholecalciferol. Synthetic-Vitamin D2 � Ergocalciferol.
27. What is the name given to fully activated vitamin D hormone?

calcitriol
28. Where are the sites of the two hydroxylations required to transform inactive vitamin D to the most potent form of systemic vitamin D?

"Liver- makes 25-OH vitamin D and Kidney makes- 1
29. Individuals with which health problem may not be able to produce sufficient vitamin D hormone?

Those withdecreased hydroxylase activity. Liver and kidney problems.
30. How does parathyroid function control blood calcium levels?

"The parathyroid glands sense the serum calcium level
31. How does vitamin D exert its effects on calcium balance?

Calcitriol will increase the amount of clacium the GI can absorbe.
32. Where in the cell is the vitamin D receptor usually found?

An intracellular nuclear receptor
33. What new information about the vitamin D receptor suggests additional roles for vitamin D in health and disease?

"Vitamin D Receptor is also found in most other cells
34. What physiological mechanisms does vitamin D influence that may impact cancer prevention?

Cell proliferation and differentiation
35. For which chronic diseases may vitamin D help lower the risk?

"Rickets
36. What are the differences between rickets and osteomalacia?

Rickets- childhood disease. Osteomalacia adult diseasae.
37. What consequences to muscle function or musculoskeletal symptomatology might be linked with vitamin D deficiency?

"A serum 25-hydroxyvitamin D level below 50 nmol/l has been associated with increased body sway and a level below 30 nmol/l with decreased muscle strength. Changes in gait
38. What is the current understanding of the potential role of vitamin D in chronic pain disorders?

"Surprising new roles for a vitamin previously associated only with calcium and bone metabolism include a potential role in treating chronic musculoskeletal pain. However
39. List the risk factors for vitamin D deficiency

"Reduced UV availability
40. What is the best laboratory indicator of vitamin D status? What daily intakes of vitamin D may be necessary to optimize this indicator?

Serum 25-OH vitamin D is best indicator. a) Less than 25 nmol/L (10 ng/mL) = Deficiency b) 40-50 nmol/L (~20 ng/mL) = Low end of �normal� lab ranges c) 75-100 nmol/L or higher (~30+ ng/mL) = recently proposed �optimum�. This would require over 1000 IU/day from diet or supplements for most people
41. How do vitamin D recommendations change as adults grow older?

They double.
42. What foods are naturally high in vitamin D? Which foods are typically fortified with vitamin D?

"Pink salmon
43. Which form of vitamin D supplement may be more potent?

D3 (cholecalciferol) is more potent than D2 (ergocalciferol)
44. Explain how vitamin D deficiency causes secondary hyperparathyroidism

Insufficient vit. D � reduced calcium absorption � compensatory PTH increase to maintain serum calcium levels (secondary hyperparathyroidism) � bone resorption
45. What amounts of vitamin D supplementation have helped prevent bone loss or reduce fracture risk?

Meta-analyses of non-vertebral fracture prevention studies in older adults found that a minimum of 700-800 IU/d is needed to reduce hip fracture and other non-vertebral fracture. 400 IU/D was not sufficient.
46. For which cancer sites is there evidence that vitamin D may play a preventive role?

Breast cancer and colorectal cancer.
47. How may vitamin D status impact immune system disorders and infectious disease?

"The immune-regulatory role of vitamin D affects both the innate and adaptive immune system contributing to the immune-tolerance of self-structures. Impaired vitamin D supply/regulation
48. What are the dangers of vitamin D toxicity?

"Excess vitamin D � hypercalcemia � kidney stones
Course Notes � Calcium
"49. In terms of bone health

what are the consequences of the need for stable
50. What is the name of the calcium containing crystal in bone?

hydroxyapatite
51. What clinical effect might the cell signaling function of calcium have on blood vessels?

"May participate in blood pressure regulation
52. On what factors does the absorption of calcium depend?

"1. Depends on size of dose (smaller doses absorbed better). 2. Depends on physiological status (better absorption in those who are calcium-deficient
53. Which calcium supplements may be taken anytime rather than only with meals?

Calcium carbonate.
"54. Describe the roles in calcium regulation of the parathyroid gland

parathyroid hormone
55. What are the most common causes of low blood calcium levels?

"A. Low blood levels usually indicate hypoparathyroidism
56. What are the consequences to bone of low dietary calcium intake in a) growing individuals and b) mature adults?

1. Failure to achieve peak bone mass in youth. 2. Failure to maintain bone mass in middle age. 3. Accelerated bone loss with aging.
57. How may dietary sodium influence the rate of bone loss in adults?

1. High intake increases urinary calcium losses
58. How does dietary protein influence calcium requirements and osteoporosis risk in humans?

Protein: high intake increases urinary calcium losses
59. What is the present understanding of the importance of caffeine consumption on calcium metabolism and bone loss?

Caffeine/Coffee: Effects are relatively minor until daily intake reaches 4 cups or more
"60. Why is there an Adequate Intake set for calcium

and not a Recommended Dietary Allowance?"
61. Which age and gender groups may be most at risk of dietary calcium inadequacy?

1. Children ages 9-18 years: 1300 mg/day. 2. Young adults: 1000 mg/day. 3. Older adults: 1200 mg/day.
62. How does typical calcium consumption by various age and gender groups compare to the Adequate Intake recommendations?

"Most age and gender groups consume far less than the Adequate Intake
"63. What food components can inhibit the absorption of calcium

and what foods contain them?"
64. What foods other than dairy products contain significant amounts of absorbable calcium?

"1. Tofu
65. Why is it not possible for multivitamin/mineral supplements to contain 100% of calcium recommendations?

The calcium would take up to much of the pill.
66. Which calcium supplement is most economical?

Calcium carbonate.
67. List the ways in which adequate calcium intake reduces the risk of bone loss and osteoporotic fractures through the life cycle.

"Increases bone mass
68. During what period of life are calcium supplements alone insufficient to slow bone loss?

Premenopausal. Supplementation does not affect bone loss in perimenopausal years when estrogen effect is lost.
69. Describe what is known about how calcium might play in colon cancer prevention?

"1. High intake (esp. with adequate vitamin D) � reduced risk of precancerous lesions
70. When is the best time to take calcium supplements to avoid increasing the risk of kidney stones?

"a) Calcium citrate taken with meals has been shown to lower risk of calcium oxalate stones
71. Calcium supplementation most effectively helps prevent what type of hypertension?

1. May help prevent pregnancy-induced hypertension. 2. Only minor effects on essential hypertension
72. What are the pros and cons of milk as a part of a healthy diet?

"A. Pro 1. Concentrated source of absorbable calcium and protein
73. How significant are the findings that high calcium or dairy intake may increase the risk of certain cancers?

"High intake of dairy products and calcium may be associated with an increased risk of prostate cancer
74. Which calcium sources have been suspected of containing lead?

"Most likely in supplements derived from natural sources (dolomite
Which minerals have been found to be less well absorbed when large amounts of calcium are also present?

"a) Most studies suggest no clinically significant interactions except in those at risk of iron
Course Notes � Phosphorus
1. In what chemical form is phosphorus typically found in the body?

Present in food and biological tissues as phosphate (PO4 �3)
2. What is hydroxyapatite?

Phosphate is the Largest concentration: hydroxyapatite in bone
"3. In addition to bone

what other structural roles does phosphorus have in the body?"
4. How are blood levels of phosphorus regulated?

"Easily absorbed by GI. Easily excreted by healthy kidneys. Affected by PTH and vitamin D along with calcium
5. How might dietary phosphorus influence calcium metabolism? What dietary sources of phosphorus are of most concern?

"High phosphorus intake has been shown to cause secondary hyperparathyroidism and bone loss in several animal models. High phosphorus
6. What is the evidence for and against claims that current phosphorus intake may be hazardous to bone health?

More research needs to be done to see if having a 4:1 phosphate to calcium diet is as harmful as they think.
7. Why is phosphorus deficiency uncommon?

Phosphate is in food additives and is abundent in protein.
8. How do recommendations for dietary phosphorus intake compare to recommendations for dietary calcium intake?

Phosphate RDA is 700 mg/day. Calcium 1200 mg/day.
9. What are the major sources of phosphorus in the diet? What sources are not naturally-occurring?

"Milk
10. Under what circumstances might calcium phosphate be desirable as a supplement?

Usually omitted from supplements unless it is part of calcium source
Course Notes and Nutrition Source � Vitamin K
11. What is the biochemical name for vitamin K produced in plants? In bacteria and animals?

"Plants- K1 � Phylloquinone. Bacteria
12. What specific form of vitamin K is used to treat osteoporosis in Japanese research?

a menaquinone called MK-4 is used in high doses for treating osteoporosis in Japanese research
13. Describe the enzymatic function that requires vitamin K

"Coenzyme required by vitamin K-dependent gamma carboxylase for coagulation
14. What are the names and functions of the proteins that depend on the vitamin K-dependent enzyme for their formation?

"Bone mineralization- Vitamin K is a coenzyme for glutamate carboxylase
15. Which drugs act by antagonizing the action of vitamin K?

anticoagulants (e.g. Warfarin)
16. Name and describe the known functions of the vitamin K-dependent proteins found in bone.

"Evidence suggests that dietary phylloquinone intake of <100 microg daily might not be optimal for bone health. Low intake of vitamin K could contribute to osteoporosis and subsequent fracture due to the undercarboxylation of osteocalcin. Low levels of circulating vitamin K have been linked with low bone density
17. What is the evidence for a role of vitamin K in preventing vascular calcification?

"Another vitamin K-dependent protein
18. What are the symptoms of overt vitamin K deficiency?

"Impaired blood clotting that may manifest as easy bruising
19. Why is vitamin K deficiency uncommon in healthy adults?

Dietary K is fairly widespread. Vitamin K is recyled in the body. 3. Gut bacteria may provide some useable K.
20. Which adults and which infants are at risk for vitamin K deficiency?

Newborns and adults on anticoagulants.
21. What is the evidence for a role of vitamin K in osteoporosis prevention?

Evidence suggests that dietary phylloquinone intake of <100 microg daily might not be optimal for bone health. Low intake of vitamin K could contribute to osteoporosis and subsequent fracture due to the undercarboxylation of osteocalcin
22. What are the best dietary sources of vitamin K? From what other source may the body receive an active form of vitamin K?

Green leafy vegetables and non-hydrogenated vegetable oils. The body can also get a non substantial amount from Intestinal bacteria (menaquinones)
23. What vitamin K-related blood test is correlated with risk of osteoporotic fractures?

Under-carboxylated osteocalcin in blood and low dietary vitamin K correlate with fracture risk
24. What is the best advice to give patients taking vitamin K antagonists regarding dietary and supplemental vitamin K intake?

Patients taking anticoagulants that are vitamin K antagonists must avoid large fluctuations in their vitamin K intake
25. What strategies are recommended by the Linus Pauling Institute for optimizing vitamin K intake?

"The Institute of Medicine's current recommended daily intake for vitamin K is 120 micrograms for men and 90 for women. Food sources: Vitamin K is found in many foods
Course notes and LPI article � Iron
1.�� Name the important heme-containing molecules in the body and describe their function.

a) Hemoglobin: oxygen-carrying protein in blood. b) Myoglobin: oxygen carrying protein in muscle. C) Cytochromes in mitochondria for electron transport.
2.�� Explain the functional importance of iron possessing two oxidation states.

Two oxidation states permits iron to act as a cofactor in oxidation-reduction reactions. 2. Intestinal absorption of ferrous iron is much better than ferric iron. 3. Iron is transported and stored as ferric ion
3.�� What factors influence iron absorption?

"Iron absorption is set up to match loss. Iron absorption is increased by a deficiency
4.�� Describe the antioxidant and pro-oxidant functions of iron

"Antioxidant- Catalase and peroxidase vs reactive peroxides. Pro-oxidant- a) Cell-killing functions of white blood cells utilize iron against infections and dysplasias
b) There is also potentially hazardous effects of excess iron on normal body tissues
"
5.�� Describe the three levels of iron deficiency. What tests would detect the earliest deficiency stages?

"Mild: depleted iron stores- 1. Plasma ferritin test- a) Good choice for early detection
6.�� Describe the appearance of red blood cells in iron deficiency anemia.

a) Microcytosis b) hypochromia.
"7.�� When older people develop iron deficiency

what potentially fatal disease may be the cause?"
8.�� List the symptoms associated with iron deficiency

"Fatigue
9.�� Which individuals are at increased risk of iron deficiency?

"Growth: ages 6 months � 4 years
10.�� Why might vegetarians be at greater risk for iron deficiency than non-vegetarians?

Vegetarians: bioavailability reduced almost 50%
11.� Why might certain athletes be at greater risk for iron deficiency?

due to increased microscopic bleeding from the gastrointestinal tract or increased fragility and hemolysis of red blood cells.
12.� How much greater are the iron requirements of menstruating and pregnant adult women compared to other adults?

Males- 8 mg/day. Menstruating women- 18mg/day.
13.� List the enhancers and the inhibitors of nonheme iron absorption.

"Influenced by dietary inhibitors- a) Phytate in legumes and whole grains b) Oxalate in spinach c) Polyphenols in fruits
14.� Which beverages are not advisable to drink with meals because they contain inhibitors of non-heme iron absorption?

"Polyphenols in fruits
15.� Which adults tend to consume less iron than the RDA?

the majority of premenopausal and pregnant women in the U.S. consume less than the RDA for iron and many men consume more than the RDA.
16.� Which foods are good sources of well-absorbed iron?

"Beef
"17.� Which foods are good sources of iron

but the iron is not well-absorbed?"
18.� What are the possible side effects of therapeutic levels of iron supplements? What measures may be taken to minimize these effects?

#N/A
19.� Under what conditions may iron interact with minerals such as zinc such that absorption is impaired?

"Iron antagonizes zinc absorption
20.� What aspect of child development may be impacted by iron status?

"The daily iron intake in children aged 1-2 years is lower than in any other age group during life. IDA during the first 2 years of life is associated with impaired mental and psychomotor development and these deficits are long lasting
21.� Explain the controversy regarding iron supplementation during pregnancy.

" Iron is present in all pre-natal supplements
"
22.� Why may iron be both helpful and detrimental to a person suffering from an infection?

"Immune system needs iron
23.� What genetic and hereditary conditions can contribute to the occurrence of iron overload?

"Hereditary haemochromatosis is a very common genetic defect in the Caucasian population
"
24.� What is the likelihood that iron from dietary or supplemental sources could increase the risk of cardiovascular diseases or certain cancers? How might this depend on individual differences in dietary sources or genetics?

"Chronic disease from excess iron 1. Probably depends on genetic susceptibility to iron overload 2. May depend on source of iron (e.g. animal sources with the more absorbable (heme) iron) 3. Some apparent relationships (e.g. meat and colorectal cancer) may be due to factors other than iron content
"
Nutrition Source � Folic acid and vitamin B12
25.� What types of birth defects are associated with folic acid insufficiency?

spina bifida and anencephaly.
26.� When must folic acid be taken to effectively reduce the risk of birth defects?

"For folate to be effective
27.� Which foods are now mandated to be fortified with folic acid?

"US Food and Drug Administration now requires that folic acid be added to most enriched breads
28.� What protein breakdown product has been linked to risk of heart disease and stroke? How do certain B vitamins participate in the recycling of this product?

"homocysteine. Folate
"
29.� What are some explanations for why some B-vitamin trials have not shown a protective effect against heart disease?

"These trials had similar designs: Adults who had a history of heart disease or stroke
30.� What is the difficulty with conducting a randomized controlled trial to find out whether folic acid supplementation reduces heart disease risk in healthy people?

"To date
31.� Explain how folic acid could decrease cancer risk in some situations but increase risk in other situations.

"Getting adequate folate may prevent polyps in people who do not have them
32.� Explain why the possible link between folic acid and increased cancer risk must be considered tentative at this time

"When teasing out the relationship between any vitamin supplement and cancer
33.� What are the best vegetarian sources of vitamin B12?

"Vitamin B12 is found naturally in animal products (such as fish
34.� List three major causes of vitamin B12 deficiency

"avoiding animal products
35.� What is the mechanism underlying pernicious anemia?

insufficient production of intrinsic factor (pernicious anemia)
36.� What are some symptoms of vitamin B12 deficiency?

"Anemia is indistinguishable from folate deficiency. 1. Oral tissue signs if severe 2. Macrocytosis with megaloblasts.
"
37.� How does high intake of folic acid make it difficult to diagnose a vitamin B12 deficiency?

One main reason for the upper limit on folic acid is that getting too much folic acid can mask the signs of a vitamin B12 deficiency.
Course notes � Folic acid
38.� How are folic acid and vitamin B12 interrelated?

Vitamin B12 is needed to recycle Folate.
39.� When is folic acid referred to as folate rather than folic acid?

"Folic acid- Stable molecule used in food fortification and supplements. Folate 1. Present in food and in body tissues 2. Natural form in food is more complex and requires adequate digestion before absorption 3. Several forms (e.g. tetrahydrofolate or TH4-folate) used in cellular processes
"
40.� Describe the one biochemical function of folate and name the important biomolecules for whose metabolism folate is critical.

One-carbon metabolism. Transfer one carbon groups around which is Critical to nucleic acid and amino acid metabolism.
41.� In what situations does folate deficiency occur?

"Once called the most common vitamin deficiency. No longer
"
42.� What type of anemia occurs as a result of folate deficiency?

"Macrocytic anemia 1. Megaloblasts 2. Hypersegmented neutrophils 3. Symptoms similar to iron or B12 deficiency
"
43.� What vitamin deficiency results in the same type of anemia as does folate deficiency?

Symptoms similar to iron or B12 deficiency
44.� Is the RDA for folate intended to help maintain normal blood homocysteine levels and prevent neural tube defects during pregnancy?

"1. Not on optimal prevention of birth defects
45.� Why is it necessary to translate micrograms of folate or folic acid into Dietary Folate Equivalents?

Needed to account for greater bioavailability of folic acid compared to more complex food folate
46.� By how much does the folate RDA for pregnancy differ from the RDA for non-pregnant adult women?

non-pregnant= 400 mcg/day. Pregnant= 600 mcg/day.
47.� Explain how gene polymorphism can change folate requirements.

"Interactions between folate and the genome are reciprocal; polymorphisms in key genes influence folate nutritional requirements
48.� What foods are now fortified with folic acid as a result of recent legislation?

Mandated in refined grain products since 1998
49.� What foods are naturally rich in folate?

"Orange juice
50.� What is the amount of supplemental folic acid that requires a prescription? What is the concern that led to restrictions on non-prescription potencies of folic acid supplements?

"Amount restricted to <1000 mcg per dose due to concerns about detecting B12 deficiency. a) When extra folate is available
51.� Why is taking folic acid supplements as soon as the woman knows she is pregnant not the best strategy for preventing neural tube defects?

1. Effective for neural tube defects only with periconceptional use (as opposed to use after pregnancy diagnosis) because the neural tube develops soon after conception.
"52.� Describe the evidence linking folic acid

homocysteine
"
53.� How may adequate folate intake help prevent cancer? For which cancer is the role of folate most promising? What factors may affect the influence of folate on cancer risk?

"1. Most promising for prevention of breast and colorectal cancer at moderate intakes
54.� When might excessive folic acid intake increase cancer risk?

"undetected precursor lesions may progress under folic acid supplementation
55.� Explain the consequences of treating a vitamin B12 deficiency anemia with folic acid.

"1. Large doses of folic acid can correct anemia (caused by vitamin B12 deficiency)
Course notes � Vitamin B12
56.� What mineral is contained in the vitamin B12 molecule?

Vitamin B12 is the largest most complex vitamin and Contains cobalt; only biological function of this mineral
57.� Describe the necessary steps for dietary B12 absorption.

"A)B12 in natural food is bound to dietary proteins
"
58.� Describe the important functions of vitamin B12.

"Recycling of activated folate for DNA synthesis. B. Catabolism of homocysteine C. Production of S-adenosylmethionine (SAM)
"
59.� Which age group is at highest risk of vitamin B12 deficiency?

"A. Affects 5-20% of the elderly
60.� Explain the difference between pernicious anemia and food-bound B12 malabsorption.

"insufficient production of intrinsic factor (pernicious anemia). Food bound-B12 malabsorption- To achieve the typical 50% absorption of vitamin B12 from dietary sources
61.� Why may supplemental B12 be more bioavailable than food B12?

B12 used in supplements and fortification is still normally absorbed since they are not bound to food components
62.� How much of a 250 mcg dose of supplemental vitamin B12 will typically be absorbed by passive diffusion in the absence of intrinsic factor? How does this amount compare to the RDA for B12?

"In the absence of adequate intrinsic factor (the primary cause of so-called pernicious anemia)
63.� Drugs that have what kind of effect on stomach function may cause reduced vitamin B12 absorption?

acid-suppressing drugs
64.� What special diet may result in a vitamin B12 deficiency?

vegan diets
65.� What vitamin deficiency results in the same type of anemia as does B12 deficiency?

Anemia is indistinguishable from folate deficiency
66.� What are the neurological signs associated with vitamin B12 deficiency?

"Neurologic symptoms- a) Probably due to myelin damage b) Can affect sensory
67.� What blood metabolites may be elevated as a result of vitamin B12 deficiency?

1. Elevated homocysteine
68.� What would be the best way to proceed clinically when a patient is diagnosed with megaloblastic anemia?

A. 500 mcg/day recommended for oral homocysteine reduction and treating deficiency in the elderly. B. 1000-2000 mcg/day is adequate for oral treatment of pernicious anemia.
69.� At what age are individuals recommended to get vitamin B12 from fortified foods or supplements?

elderly 51 and older are advised to get B12 from unbound sources.
70.� How much vitamin B12 is sufficient to produce a significant reduction in homocysteine levels?

500 mcg/day recommended for oral homocysteine reduction and treating deficiency in the elderly
71.� Where in nature is vitamin B12 synthesized? How does this relate to potential food sources of B12?

"All B12 in nature is synthesized by bacteria. 1. Including gut bacteria in ruminant animals
72.� How does the average intake of vitamin B12 by young adults compare to the RDA?

A. B12 intake exceeds RDA in young adults and many older adults on Western diets. 1. But malabsorption places older adults at risk
73.� How much folic acid and vitamin B12 optimally stabilized chromosomes in a dose-response trial?

"Methylation of DNA
74.� What are the possible mechanisms by which vitamin B12 deficiency might raise the risk of cognitive disorders such as Alzheimer's disease?

"Other possible B12 prevention effects (e.g. neural tube defects

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Author:	bbeckers88
ID:	115912
Filename:	test 3.csv
Updated:	2011-11-10 15:27:26
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Description:	micro 2 test 3
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