,26/27 BIOL 121/BIOD 121 MODULE 4 EXAM |
NUTRITION -PORTAGE | Q&A + DETAILED
RATIONALES
1. A student compares the four major Dietary Reference Intake categories. Which value
represents the average daily intake estimated to meet the nutrient requirement of
nearly all healthy individuals in a particular life-stage and sex group?
A) Estimated Average Requirement
B) Adequate Intake
C) Recommended Dietary Allowance
D) Tolerable Upper Intake Level
Correct Answer: Recommended Dietary Allowance
Rationale: The Recommended Dietary Allowance (RDA) is designed to meet the nutrient
needs of nearly all healthy individuals in a defined life-stage and sex group. The Estimated
Average Requirement (EAR) meets the estimated requirement of about half of healthy
individuals in a group and is used in establishing the RDA. An Adequate Intake (AI) is
used when evidence is insufficient to establish an EAR and RDA. The Tolerable Upper
Intake Level (UL) identifies the highest usual daily intake unlikely to pose appreciable risk
of adverse effects.
2. Researchers lack enough evidence to establish an EAR for a nutrient but have sufficient
observational or experimental information to recommend an intake level. Which
reference value is most appropriate?
A) Adequate Intake
B) Recommended Dietary Allowance
C) Tolerable Upper Intake Level
D) Daily Value
Correct Answer: Adequate Intake
Rationale: An Adequate Intake is established when evidence is insufficient to determine an
EAR and therefore an RDA cannot be calculated. The AI is based on observed or
experimentally determined estimates of intake in apparently healthy populations. It should
not be interpreted as equivalent to a precisely established RDA.
3. An adult routinely takes several fortified foods plus a high-dose supplement and wants
to evaluate the possibility of nutrient toxicity. Which Dietary Reference Intake is most
directly relevant?
A) EAR
B) UL
C) RDA
D) AI
,Correct Answer: UL
Rationale: The Tolerable Upper Intake Level is the highest average daily nutrient intake
expected to pose little risk of adverse effects for most healthy people. Intake above the UL
does not guarantee toxicity, but the probability of adverse effects generally increases as
intake rises above it. The RDA and AI concern nutritional adequacy rather than toxicity.
4. Why should an individual not interpret an RDA as the minimum amount below which
deficiency immediately occurs?
A) RDAs apply only to supplements
B) RDAs represent toxicity thresholds
C) Nutrient requirements are identical among all people
D) The RDA includes a margin intended to cover nearly all healthy individuals whose
requirements vary
Correct Answer: The RDA includes a margin intended to cover nearly all healthy
individuals whose requirements vary
Rationale: Individual nutrient requirements vary. An RDA is intentionally set high enough
to meet the needs of nearly all healthy individuals in its target group. A person's intake
below the RDA therefore does not automatically establish deficiency; assessment requires
consideration of usual intake, physiological status, clinical findings, and sometimes
biochemical measures.
5. Vitamins differ fundamentally from energy-yielding macronutrients because vitamins:
A) provide 4 kcal per gram
B) provide 9 kcal per gram
C) are organic micronutrients needed for physiological functions but do not themselves
supply usable caloric energy
D) are inorganic elements required only for bone formation
Correct Answer: are organic micronutrients needed for physiological functions but do not
themselves supply usable caloric energy
Rationale: Vitamins are organic compounds required in relatively small amounts for
functions such as coenzyme activity, vision, antioxidant protection, blood formation, and
regulation of gene expression. Unlike carbohydrate, fat, and protein, vitamins do not
themselves provide calories. Minerals are inorganic elements rather than organic
compounds.
6. A nutrition student is asked to classify vitamins according to their major absorption
and storage characteristics. Which grouping contains only fat-soluble vitamins?
A) B1, B2, B6, B12
B) A, D, E, K
C) C, B6, folate, B12
D) A, C, D, folate
, Correct Answer: A, D, E, K
Rationale: Vitamins A, D, E, and K are fat soluble. Their absorption generally occurs along
with dietary lipids and depends on normal fat digestion and absorption. The B vitamins
and vitamin C are water soluble.
7. A disorder severely impairs intestinal fat absorption. Which nutritional consequence
should receive particular attention?
A) Reduced absorption of sodium only
B) Inability to absorb every B vitamin
C) Increased synthesis of vitamin C
D) Increased risk of deficiencies of vitamins A, D, E, and K
Correct Answer: Increased risk of deficiencies of vitamins A, D, E, and K
Rationale: Fat-soluble vitamins depend substantially on normal lipid digestion, micelle
formation, and intestinal absorption. Chronic fat malabsorption can therefore compromise
vitamins A, D, E, and K simultaneously. The mechanism illustrates why gastrointestinal
disease can produce micronutrient deficiencies even when dietary intake appears adequate.
8. Compared with many water-soluble vitamins, fat-soluble vitamins generally have a
greater potential to:
A) be stored in body tissues and accumulate with excessive intake
B) disappear completely in urine immediately after absorption
C) provide dietary energy
D) function only in extracellular fluid
Correct Answer: be stored in body tissues and accumulate with excessive intake
Rationale: Fat-soluble vitamins can be stored in the liver and adipose tissue to varying
degrees. Consequently, excessive supplemental intake can lead to accumulation and toxicity
more readily for some fat-soluble vitamins. Water-soluble vitamins generally have more
limited storage, although important exceptions exist, particularly vitamin B12.
9. Vitamin A is especially important for:
A) converting fibrinogen into fibrin exclusively
B) forming thyroid hormone
C) maintaining vision, epithelial tissues, immune function, and normal cellular
differentiation
D) serving as the body's principal extracellular electrolyte
Correct Answer: maintaining vision, epithelial tissues, immune function, and normal
cellular differentiation
NUTRITION -PORTAGE | Q&A + DETAILED
RATIONALES
1. A student compares the four major Dietary Reference Intake categories. Which value
represents the average daily intake estimated to meet the nutrient requirement of
nearly all healthy individuals in a particular life-stage and sex group?
A) Estimated Average Requirement
B) Adequate Intake
C) Recommended Dietary Allowance
D) Tolerable Upper Intake Level
Correct Answer: Recommended Dietary Allowance
Rationale: The Recommended Dietary Allowance (RDA) is designed to meet the nutrient
needs of nearly all healthy individuals in a defined life-stage and sex group. The Estimated
Average Requirement (EAR) meets the estimated requirement of about half of healthy
individuals in a group and is used in establishing the RDA. An Adequate Intake (AI) is
used when evidence is insufficient to establish an EAR and RDA. The Tolerable Upper
Intake Level (UL) identifies the highest usual daily intake unlikely to pose appreciable risk
of adverse effects.
2. Researchers lack enough evidence to establish an EAR for a nutrient but have sufficient
observational or experimental information to recommend an intake level. Which
reference value is most appropriate?
A) Adequate Intake
B) Recommended Dietary Allowance
C) Tolerable Upper Intake Level
D) Daily Value
Correct Answer: Adequate Intake
Rationale: An Adequate Intake is established when evidence is insufficient to determine an
EAR and therefore an RDA cannot be calculated. The AI is based on observed or
experimentally determined estimates of intake in apparently healthy populations. It should
not be interpreted as equivalent to a precisely established RDA.
3. An adult routinely takes several fortified foods plus a high-dose supplement and wants
to evaluate the possibility of nutrient toxicity. Which Dietary Reference Intake is most
directly relevant?
A) EAR
B) UL
C) RDA
D) AI
,Correct Answer: UL
Rationale: The Tolerable Upper Intake Level is the highest average daily nutrient intake
expected to pose little risk of adverse effects for most healthy people. Intake above the UL
does not guarantee toxicity, but the probability of adverse effects generally increases as
intake rises above it. The RDA and AI concern nutritional adequacy rather than toxicity.
4. Why should an individual not interpret an RDA as the minimum amount below which
deficiency immediately occurs?
A) RDAs apply only to supplements
B) RDAs represent toxicity thresholds
C) Nutrient requirements are identical among all people
D) The RDA includes a margin intended to cover nearly all healthy individuals whose
requirements vary
Correct Answer: The RDA includes a margin intended to cover nearly all healthy
individuals whose requirements vary
Rationale: Individual nutrient requirements vary. An RDA is intentionally set high enough
to meet the needs of nearly all healthy individuals in its target group. A person's intake
below the RDA therefore does not automatically establish deficiency; assessment requires
consideration of usual intake, physiological status, clinical findings, and sometimes
biochemical measures.
5. Vitamins differ fundamentally from energy-yielding macronutrients because vitamins:
A) provide 4 kcal per gram
B) provide 9 kcal per gram
C) are organic micronutrients needed for physiological functions but do not themselves
supply usable caloric energy
D) are inorganic elements required only for bone formation
Correct Answer: are organic micronutrients needed for physiological functions but do not
themselves supply usable caloric energy
Rationale: Vitamins are organic compounds required in relatively small amounts for
functions such as coenzyme activity, vision, antioxidant protection, blood formation, and
regulation of gene expression. Unlike carbohydrate, fat, and protein, vitamins do not
themselves provide calories. Minerals are inorganic elements rather than organic
compounds.
6. A nutrition student is asked to classify vitamins according to their major absorption
and storage characteristics. Which grouping contains only fat-soluble vitamins?
A) B1, B2, B6, B12
B) A, D, E, K
C) C, B6, folate, B12
D) A, C, D, folate
, Correct Answer: A, D, E, K
Rationale: Vitamins A, D, E, and K are fat soluble. Their absorption generally occurs along
with dietary lipids and depends on normal fat digestion and absorption. The B vitamins
and vitamin C are water soluble.
7. A disorder severely impairs intestinal fat absorption. Which nutritional consequence
should receive particular attention?
A) Reduced absorption of sodium only
B) Inability to absorb every B vitamin
C) Increased synthesis of vitamin C
D) Increased risk of deficiencies of vitamins A, D, E, and K
Correct Answer: Increased risk of deficiencies of vitamins A, D, E, and K
Rationale: Fat-soluble vitamins depend substantially on normal lipid digestion, micelle
formation, and intestinal absorption. Chronic fat malabsorption can therefore compromise
vitamins A, D, E, and K simultaneously. The mechanism illustrates why gastrointestinal
disease can produce micronutrient deficiencies even when dietary intake appears adequate.
8. Compared with many water-soluble vitamins, fat-soluble vitamins generally have a
greater potential to:
A) be stored in body tissues and accumulate with excessive intake
B) disappear completely in urine immediately after absorption
C) provide dietary energy
D) function only in extracellular fluid
Correct Answer: be stored in body tissues and accumulate with excessive intake
Rationale: Fat-soluble vitamins can be stored in the liver and adipose tissue to varying
degrees. Consequently, excessive supplemental intake can lead to accumulation and toxicity
more readily for some fat-soluble vitamins. Water-soluble vitamins generally have more
limited storage, although important exceptions exist, particularly vitamin B12.
9. Vitamin A is especially important for:
A) converting fibrinogen into fibrin exclusively
B) forming thyroid hormone
C) maintaining vision, epithelial tissues, immune function, and normal cellular
differentiation
D) serving as the body's principal extracellular electrolyte
Correct Answer: maintaining vision, epithelial tissues, immune function, and normal
cellular differentiation
