Unlock document.
This document is partially blurred.
Unlock all pages and 1 million more documents.
Get Access
184
Study Card 10 Answer Key
1. c 2. a
4. The body can make niacin from the amino acid tryptophan once protein synthesis needs have been met.
5. Folate occurs in foods mostly in its bound or polyglutamate form. This is digested to monoglutamate, which is
then attached to a methyl group (CH3) and delivered to the liver and other body cells. To activate folate, the
6. Large doses of nicotinic acid from supplements or drugs produce a variety of pharmacological effects, most
notably “niacin flush.” Niacin flush occurs when nicotinic acid is taken in doses only three to four times the
RDA. It dilates the capillaries and causes a tingling sensation that can be painful. (Large doses of nicotinic acid
may be prescribed to lower LDL cholesterol, raise HDL cholesterol, and increase adiponectin levels in people at
Critical Thinking Questions9
1. Explain how bioavailability affects the functionality of vitamins within the body. Discuss how food preparation
methods affect vitamin bioavailability.
2. Even though vitamins are not considered to be energy-yielding nutrients they play a required role in
metabolism. How do they accomplish this task? Identify the significant roles of B complex vitamins in
metabolism.
3. Describe a unique source of niacin and a unique function of niacin in the body.
4. Explain the features of folate that are associated with health promotion measures and prevention of disease.
5. Historically, nutritional deficiencies were not often recognized as a cause for disease. Many deficiency
symptoms were attributed incorrectly to infectious disease processes. In view of this historical perspective, how
are the clinical deficiency states of beriberi and pellagra different in terms of their clinical etiology? What
factors contribute to the existence of these specific deficiency states?
6. Discuss the differences among anemias associated with B vitamin deficiency states. Why is it potentially
difficult to diagnose B complex vitamin deficiency states?
185
Answer Key
1. In order for the body to utilize vitamins, factors favorable to absorption are warranted. Factors such as the
vitamin source (natural or synthetic), food content association, method of preparation, efficiency of digestion,
and baseline nutritional status all interact to affect absorption. Certain conditions related to any of these factors
2. B complex vitamins function as participants in coenzymes in the metabolic pathway. As such they provide an
essential function in helping the body to derive energy from the breakdown of nutrients from food sources.
Other B vitamins play significant roles in the metabolism of amino acids and formation of red blood cells.
Thiamin: coenzyme TPP (thiamin pyrophosphate) helps to convert pyruvate to acetyl CoA and participation in
3. A unique source of niacin is its synthesis from the amino acid tryptophan in the liver. It is the only vitamin that
can be produced in the body from dietary protein. A unique function of niacin (when administered in very large
4. Clinical evidence has established that folic acid deficiencies among pregnant women are associated with neural
tube defects in their infants. Folic acid is also needed for the breakdown of homocysteine, an amino acid that is
correlated with the presence of heart disease. Folic acid also has a complex relationship with cancer. Thus, the
5. Both beriberi and pellagra are associated with specific B vitamins, thiamin and niacin, respectfully, in terms of
single-nutrient dietary deficiencies. They have occurred over large populations as a result of inadequate dietary
intake, in contrast to other B complex vitamin deficiency states, which result from individual genetic pathways
186
6. A clinical deficiency in vitamin B6 can result in the development of a microcytic anemia. Diagnostic labs will
reveal a decrease in red blood cells, hemoglobin, and hematocrit. Neurological manifestations also can occur
(confusion and convulsions). Integument changes such as scaly dermatitis can present along with depression.
A clinical deficiency in folic acid can result in the development of a macrocytic anemia (specifically,
megaloblastic anemia). Diagnostic labs will also reveal a decrease in red blood cells, hemoglobin, and
blood work to identify specific B vitamin deficiencies. Diagnostic lab tests identifying cell morphology are
required along with individual serum level testing to be able to accurately diagnose the type of anemia that is
present. If the anemia results from a B vitamin deficiency, then the typical treatment of iron replacement
therapy will not adequately solve the problem. Additionally, further deterioration of neurological functioning
can occur, and that may lead to poorer health outcomes.
IM Worksheet Answer Key
Worksheet 10-1 – Answers will vary.
Worksheet 10-2: Bioavailability Concept
Situations
↓ Bioavailability
Minimal effect on
bioavailability
↑ Bioavailability
Par boiling
Worksheet 10-4: Water-Soluble Vitamin Review (Internet Exercise)
1. b
2. b
3. a
4. a and b
5. b
Worksheet 10-6: Chapter 10 Crossword Puzzle
188
Worksheet 10-1: Vitamin History in Clinical Research
1. Perform a web-based search in Pub Med or Science Direct for the following: thiamin vitamin history, niacin
vitamin history, and ascorbic acid vitamin history.
2. How many articles did you find on each vitamin?
Consider the following questions using a round table approach:
• In terms of scientific evidence do we have a long history of information with respect to thiamin, niacin, or
ascorbic acid?
189
Worksheet 10-2: Bioavailability Concept
For the following situations, indicate whether or not the bioavailability of a food’s vitamin
content would be affected, negatively and/or positively. (Choose all that apply.)
Situations
↓ Bioavailability
Minimal effect on
bioavailability
↑ Bioavailability
Par boiling
Microwaving
190
Worksheet 10-3: Vitamins in Your Diet
A diet that offers a variety of foods from each group, prepared with reasonable care, serves up ample
vitamins. The grains group delivers thiamin, riboflavin, niacin, and folate. The fruit and vegetable groups
excel in folate, vitamin C, vitamin A, and vitamin K. The protein foods group serves thiamin, niacin,
vitamin B6, and vitamin B12. The dairy group stands out for riboflavin, vitamin B12, vitamin A, and
vitamin D. Even the oils group with its vegetable oils provides vitamin E. Determine whether these food
choices are typical of your diet.
Food choices
Frequency per week
Citrus fruits
Dark green, leafy vegetables
1. Do you eat dark green, leafy or deep yellow vegetables daily?
2. Do you drink vitamin A- and D-fortified milk regularly?
191
Worksheet 10-4: Water-Soluble Vitamin Review (Internet Exercise)
1. Which of the B vitamins is most sensitive to light?
a. Folic acid
b. Riboflavin
c. Pantothenic acid
d. Biotin
2. The ingestion of water-soluble vitamins does not cause any side effects or adverse reactions due to
3. The stability of some water-soluble vitamins is affected by alkaline solutions.
4. Which water-soluble vitamin helps participate in protein metabolism? Select ALL that apply.
5. Pernicious anemia occurs as a result of thiamin deficiency.
a. True
b. False
6. Match the vitamin with its corresponding pertinent information.
a. Biotin
b. Folic acid
c. Ascorbic acid
192
Worksheet 10-5: Vitamin/Mineral Supplement Evaluation
Select a supplement to evaluate and respond to the following questions about it.
1. What is the name of the supplement?
4. Are most vitamins and minerals present in amounts at or near 100% of the adult DRI? Exceptions include
biotin, calcium, magnesium, and phosphorus, which are rarely found in amounts near 100% of the DRI. List any
vitamins or minerals that are present in low amounts or dangerously high amounts.
5. Does the supplement contain unnecessary nutrients or nonnutrients? If yes, list them.
193
Worksheet 10-6: Chapter 10 Crossword Puzzle
1
2
3
4
5
6
7
8
9
10
Across:
Down:
2. Vitamin B12 deficiency is common in elderly adults
due to _____.
5. Vitamins are best absorbed when consumed from
_____.
9. Diarrhea and gastrointestinal distress can be side
effects of excessive _____ intake.
10. _____ can be prescribed to therapeutically lower
cholesterol levels.
1. _____-soluble vitamins are found in the watery
compartments of foods.
4. Chronic alcoholics are often deficient in the vitamin
_____.
intake of _____ in early pregnancy is essential.
6. Nutrients that facilitate the release of energy from
foods but don’t provide energy
8. Vitamin B12 is found almost exclusively in _____-
194
Handout 10-1: RDA/AI and UL for Vitamins Compared
