nutrition ch.13
What happens to choline in the body?
-Converted to betaine -Excreted in the urine
Where is folate excreted?
-Feces -Urine
Which of the following are good food sources of vitamin B-6?
-Fish -Poultry -Meat
How do we get choline into the body?
-Food intake -Synthesized by the body
Select the populations that are at risk of developing a thiamin deficiency.
-those with gastrointestinal disease -heart failure patients -those who are obese
Good food sources of biotin include ____.
-whole grains -mushrooms -nuts and legumes
60 mg of tryptophan will produce ____ mg of niacin.
1
The Upper Level of vitamin B-6 has been set at _____.
100 mg/day
When folic acid is consumed as a supplement, without food, it is ______ bioavailable.
100%
How many milligrams of tryptophan are required to yield 200 mg of niacin?
12,000
The average meat-eating person has enough vitamin B-12 stored in the liver to last for _____.
2 to 3 years
What is the AI for biotin?
30 μg for men and women
The RDA for vitamin C in smokers is _____ higher than those who do not smoke.
35 mg/day
The RDA for folate for adults, expressed as DFE is _____.
400 μg/day
Where is the main storage site for vitamin B-6?
Muscle
NAD+ and NADP+ are coenzyme forms of which B vitamin?
Niacin
Which B-vitamin is synthesized from tryptophan?
Niacin
Which B-vitamin is found in a wide variety of foods?
Pantothenic acid
Which B-vitamin is used throughout the body in energy metabolism and is part of coenzyme A?
Pantothenic acid
Which is true about the Upper Level for thiamin?
There is no Upper Level established for this nutrient.
Biotin functions as a(n) ______ for several carboxylase enzymes that add carbon dioxide to various compounds.
coenzyme
Niacin serves as a ______ in energy metabolism.
coenzyme
Coenzymes play an important role in metabolism because they _____.
aid in the function of activating enzymes
Generally, _______ niacin that is consumed is absorbed.
almost all
Those consuming megadoses of vitamin C should alert their physicians of this since megadoses can ______.
alter the results of tests for blood in the stool
Adults generally get _______ intake of pantothenic acid to sustain health.
an adequate
Vitamin B-12 is found in ______ foods only.
animal
Most animals, unlike humans, do not need a daily source of vitamin C because they ___.
are able to synthesize the vitamin
Unlike most animals, humans ______ able to synthesize vitamin C.
are not
In infants with a deficiency of ____, symptoms include skin rash, hair loss, convulsions, and impaired growth.
biotin
Thiamin is a key component required to metabolize the macronutrient ______.
carbohydrate
The essential nutrient that helps prevent fat from accumulating in the liver and is an important source of methyl groups in many body reactions is _____.
choline
Which food groups provide the highest levels of vitamin C in the body?
citrus fruits and green vegetables
The microcytic hypochromic anemia associated with a vitamin B-6 deficiency arises due to ______.
decreased hemoglobin synthesis
Symptoms of a folate deficiency include _____.
decreased red blood cell synthesis
There _____ appear to be adverse effects from consuming large amounts of riboflavin.
does not
One of vitamin C's main functions in the body is to _____.
donate electrons in oxidation-reduction reactions
Grain products that have been milled are ______ with B-vitamins and the mineral iron to lessen the risk of deficiency.
enriched
Intake of vitamin B-12 from foods in the United States typically ______ the RDA.
exceeds
Enriched grain products remain low in ______.
fiber
The water-soluble vitamin deficiency that may eventually lead to megaloblastic anemia is due to a lack of which vitamin?
folate
Which B-vitamin is critical for DNA synthesis and amino acid metabolism?
folate
The synthetic form(s) of the B vitamin folate is (are) called ______.
folic acid
The highest folate content may be obtained from eating ____.
fresh fruits and vegetables
There is no UL set for riboflavin because it _____.
has limited absorption and rapid excretion, with no known adverse effects from consuming large quantities
Vitamin B-12 is required for an enzymatic reaction involved in _____ metabolism.
homocysteine
An increase in vitamin C intake results in a(n) ______ of excretion of the vitamin by the kidneys.
increase
When either folate or vitamin B-12 is lacking, the amount of homocysteine in the body ______.
increases
Pernicious anemia is related to the inadequate production of the ______ required for vitamin B-12 absorption.
intrinsic factor
Although Adequate Intakes are set for choline, it may be that the choline requirement ______ by the body's synthesis of the vitamin.
is met
White bread ______ a good source of vitamin B-6 because it is lost in the refining of grain and ______ added back during refinement.
is not; is not
Choline has not been classified as a B vitamin because _____.
it does not have a coenzyme function
Foods of animal origin are ______ contributors of choline to the diet.
large
The prevalence of thiamin deficiency in older adults is ____.
less common than thought
Most adults ______ the adequate intake level for biotin.
meet
Food sources of choline include _____.
milk eggs, chicken, and beef
The generic name of the B-vitamin folate refers to the form of the vitamin found _____.
naturally in foods
The UL for vitamin B-6 has been established due to the risk of _____.
nerve damage
A folate deficiency during pregnancy increases the risk for ______.
neural tube defects
To account for preformed niacin in foods and niacin synthesized from tryptophan, niacin is expressed as ____.
niacin equivalents
The function of PLP, the coenzyme form of vitamin B-6, pertains mainly to enzymatic reactions involving ______.
nitrogen-containing compounds
Vitamin B-6 participates in ______ metabolic reactions.
numerous
The absorption of vitamin B-6 is by ______ diffusion.
passive
Corn-based diets are associated with which condition?
pellagra
The deficiency disease for vitamin B-12 is called _____.
pernicious anemia
Biotin deficiencies are _____.
rare
Milk is an excellent source of ____.
riboflavin
The deficiency disease for vitamin C is called ______.
scurvy
Water-soluble vitamins are essential organic substances needed in _____ amounts.
small
The pantothenic acid portion of coenzyme A is released during digestion in the ____.
small intestine
Where does the absorption of vitamin C occur?
small intestine
Smokers need more vitamin C daily than nonsmokers because _____.
smoking increases vitamin C turnover
Which organ produces the intrinsic factor that enhances vitamin B-12 absorption?
stomach
Due to its potency, a UL has been set for _____.
synthetic folic acid only
Pork products are excellent sources of _____.
thiamin
The B vitamin required as a coenzyme to metabolize carbohydrates and some amino acids is _____.
thiamin
Choline is absorbed from the small intestine by way of ______ proteins.
transport
Vitamin B-6 has a long history as a treatment for _____.
-premenstrual syndrome -nausea during pregnancy
The food sources of riboflavin include _____.
-spinach -mushrooms -liver
This vitamin's discovery was linked to "egg-white injury."
Biotin
Which vitamin helps maintain gene stability by binding to the proteins that help DNA fold in the cell nucleus?
Biotin
What is the enzyme responsible for the breakdown of biotin?
Biotinidase
Which vitamin is not associated with a deficiency disease?
Choline
What combines with inactive enzymes to form active enzymes able to catalyze specific reactions?
Cofactors
The coenzymes of which B-vitamin are needed for the synthesis and maintenance of new cells?
Folate
Why would consuming fresh fruits and vegetables contribute more folate?
Folate is destroyed by heat.
The coenzyme form of pantothenic acid participates in _______.
-fatty acid synthesis -the breakdown of carbohydrates, protein, alcohol, and fats
Identify the food sources of thiamin
-legumes -sunflower seeds
Damage to the ______ has been observed in adults fed choline-deficient diets.
-liver -muscle
Side effects of excessive intake of choline include ______.
-low blood pressure -fishy body odor
Common food sources for pantothenic acid include _____.
-meat -milk
Choline functions as a part of _____.
-phospholipids such as lecithin -acetylcholine
Why are corn-based diets associated with pellagra?
-Niacin in corn is unavailable. -Corn contains little tryptophan.
Which of the following statements are true about pantothenic acid?
-Present in all body cells and supplied by a variety of foods -Pantothenic is from the Greek word pantothen, meaning "from every side."
What are the 3 different forms of vitamin B-6?
-Pyridoxine -Pyridoxal -Pyridoxamine
Which of the following are characteristics of pantothenic acid?
-Storage is minimal -Part of coenzyme A -Transported bound to red blood cells
Which is true about the transport and storage of thiamin?
-Transported by red blood cells -Little thiamin is stored in the body
Water-soluble vitamins ______.
-are needed for the normal function of body tissues -are needed for the growth of body tissues -help maintain body tissues
Functions of riboflavin include ______.
-assisting antioxidant reactions -energy-yielding metabolism
Biotin is found in food as _____.
-biocytin -free biotin
The signs of scurvy include ____
-bone pain -slowed wound healing -bleeding gums
The signs of scurvy include ____.
-bone pain -slowed wound healing -bleeding gums
Which of the following are good sources of vitamin C?
-citrus fruits -red peppers -broccoli
Biotin participates in reactions called carboxylations. Which of the following is the best definition of carboxylations?
Adding carbon dioxide to compounds
How are folate requirements expressed?
Dietary folate equivalents (DFE)
What happens to excess niacin?
Excreted in the urine
What substance produced by the digestive system is necessary in order to absorb vitamin B-12?
Intrinsic factor
A deficiency in which of the following vitamins may cause glossitis?
Riboflavin
Which B-vitamin is a component of flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD)?
Riboflavin
Where does the breakdown of biotin occur?
Small intestine
Where is thiamin absorbed?
Small intestine
Which of the following DRIs has not been set for pantothenic acid?
Upper Level
Which vitamin has foods of animal origin as its only reliable food source and is the only vitamin that contains a mineral as part of its structure?
Vitamin B-12
Which vitamin is also known as cobalamin?
Vitamin B-12
What vitamin is needed by nearly all amino acids for metabolism?
Vitamin B-6
High doses of this vitamin cause adverse gastrointestinal effects and can give false results in medical tests for blood in the stool.
Vitamin C
Which vitamin has been thought to prevent/cure the common cold, although little research has confirmed this claim?
Vitamin C
Which water-soluble vitamin acts as an electron donor and has a cofactor role for several metalloenzymes?
Vitamin C
The best source of vitamin B-12 would be _____.
a hamburger
Glossitis results in _____.
a painful, inflamed tongue
The average daily intake for thiamin in men and women is ______ the recommended RDA.
above
Dietary folate equivalents (DFE) reflect the differences in the ______ of food folate and synthetic folic acid.
absorption
Coenzyme A, the coenzyme form of pantothenic acid, is essential for the formation of ______.
acetyl-CoA
Current research shows that vitamin C has a _______ effect on preventing and treating the common cold.
very modest
Since a high folic acid intake may mask a ______ deficiency, the FDA limits the amount of folic acid in nonprescription supplements.
vitamin B-12
Seborrheic dermatitis, microcytic hypochromic anemia, convulsions, depression, and confusion are symptoms of ______ deficiency.
vitamin B-6
Which vitamin has been used to treat carpal tunnel syndrome?
vitamin B-6
