Chapter 12 Study Guide Flashcards
How do B vitamins play key roles in metabolism?
acting as coenzymes or cofactors
High bioavailability is characteristic of which vitamins?
B vitamins
What percentage of consumed B vitamins are absorbed?
50-90%
What is the nutritional health of North Americans regarding B vitamins?
adequate
Many common foods are _________ with one or more of the B vitamins
fortified
B vitamins are _____-soluble
water
What percentage of B vitamins are lost during food processing?
10-25%
Which cooking methods are best for preserving B vitamin content?
stir-frying, steaming, microwaving
B vitamin deficiency is likely to occur among what populations?
developing countries, older adults, people with inadequate dietary patterns, people with alcohol use disorders
The process of refining grains leads to what?
loss of B vitamins, other vitamins and minerals
Which parts of grains are lost during milling?
seeds, germ, bran, husk layers
What is remaining in refined grains?
starch-containing endosperm
What is lost in grains as a result of discarding seeds, germ, bran, and husk layers?
nutrients
What four B vitamins are refined grains enriched with to counteract nutrient losses?
thiamin, riboflavin, niacin, folic acid, along with iron
Are refined grain products as nutritious as whole grains?
no
What side effect is shown in short term loss of B vitamins?
fatigue
What side effects shown in long-term loss of B vitamins?
cardiovascular disease, cancers, cataracts
What is one of the primary functions of thiamin?
help release energy from carbohydrate
What is the coenzyme form of thiamin?
thiamin pyrophosphate
What does thiamin pyrophosphate do?
participates in reactions in which carbon dioxide is released during breakdowns of carbs and certain amino acids
Thiamin also functions in chemical reactions that make what?
RNA, DNA, neurotransmitters
What is thiamin-deficiency disease called?
beriberi
beriberi means
“I can’t, I can’t” in the Sri Lanka language of Sinhalese
Describe symptoms of beriberi
weakness, loss of appetite, irritability, nervous tingling, poor arm and leg coordination, deep muscle pain in calf, enlarged heart, severe edema.
Beriberi is prevalent in areas where _______ is a staple food
rice
Beriberi is likely to occur if an individual consumes _____ rice over ______ rice
white, brown
White rice in North America is usually enriched in _____
thiamin
Describe the process of how beriberi happens
when glucose (primary fuel for brain and nerve cells) cannot be metabolized to release energy because of the lack of thiamin
List the first signs of a thiamin deficiency
brain and nerve action, problems with functions that depend on glucose.
What is the relationship between alcohol abuse and thiamin?
absorption of thiamin is profoundly diminished and excretion is increased by alcohol
Beriberi associated with alcohol use disorders is also called what?
Wernicke-Korsakoff syndrome
List other groups of people at risk of thiamin deficiency
older people, people with HIV, diabetes, people who have undergone bariatric surgery
Describe the intakes of thiamin for men and women
men exceed the DV by 50 percent or more, women meet the RDA.
What is the RDA of thiamin for men?
1.2 mg
What is the RDA of thiamin for women?
1.1 mg
What is the DV of thiamin?
1.2 mg
What is the Upper Level of thiamin?
none
Why is there no upper level for thiamin?
thiamin is rapidly lost in the urine and no toxicity has been observed from the use of oral thiamin supplements
List major sources of thiamin
pork products, wheat germ, ready to eat breakfast cereals, enriched grains and flours, green beans, milk, orange juice, organ meats, peanuts, dried beans, seeds
Which sections of MyPlate has the most thiamin?
protein and grain
Refined grain products remain lower in what nutrients?
Vitamins E and B-6, potassium, magnesium, fiber
Where does riboflavin derive its name from?
yellow color, flavus means yellow in Latin
What are the coenzyme forms of riboflavin?
flavin dinucleotide and flavin mononucleotide
What do flavin dinucleotide and flavin mononucleotide do?
participate in many energy-yielding metabolic pathways, such as the breakdown of fatty acids.
Some metabolism of vitamins and minerals require _________
riboflavin
What role does riboflavin indirectly have?
antioxidant role through its support of the enzyme glutathione peroxidase.
List symptoms of ariboflavinosis
inflammation of the mouth and tongue, dermatitis, eye disorders, sun sensitivity, confusion.
Why does riboflavin deficiency occur with deficiencies of niacin, thiamin, and vitamin B-6?
these nutrients often occur in the same foods.
What is glossitis?
soreness or inflammation of the tongue
What does glossitis signal?
a deficiency of riboflavin, niacin, vitamin B-6, folate, or vitamin B-12
What is angular cheilitis?
inflammation of the corners of the mouth that may cause painful cracking
Are daily intakes of riboflavin above the RDA?
yes
Why do people with alcohol use disorders risk riboflavin deficiency?
their eating patterns have low nutrient density
List people at risk for riboflavin deficiency
vegetarian athletes, vegan diets, women who are pregnant
What is the Upper intake level for riboflavin?
none
Why is there no UL for riboflavin?
no observable symptoms indicate riboflavin taken in megadose levels
Because we excrete excess riboflavin, riboflavin can cause the urine to become bright __________
yellow
What is the RDA of riboflavin for men and women?
men—1.3 mg, women—1.1 mg
what is the DV of riboflavin
1.3 mg
angular cheilitis is also called?
cheilosis or angular stomatitis
Which sections of MyPlate contain the most nutrient-dense sources of riboflavin?
grains, dairy, protein groups
List food sources of riboflavin
breakfast cereals, milk, dairy products, enriched grains, meat, and eggs
List vegetable sources of riboflavin
asparagus, broccoli, various greens
riboflavin is destroyed by _______
light
riboflavin can be produced by bacteria in the __________ intestine
large
more riboflavin is absorbed after consumption of ________-based foods compared to _________-based foods
vegetable, meat
Niacin functions in body as one of what two related compounds?
nicotinic acid and nicotinamide
what are the coenzyme forms of niacin?
nicotinamide dinucleotide or nicotinamide dinucleotide phosphate
Niacin cofactors are used in generating energy by burning ______ and ______
carbs, fat
Nicotinic acid is said to what?
lower blood lipids including LDL cholestrol
the group of niacin-deficiency symptoms is known as _______
pellagra
symptoms of pellagra are what?
dementia, diarrhea, dermatitis, death
pellagra was prevalent in populations that consumed _____
corn
niacin in corn is bound by a protein that ________ its absorption
inhibits
soaking corn in an alkaline solution _________ niacin and renders it _______ bioavailable
releases, more
list people at risk of pellagra
chronic alchool use disorders, poverty, malnutriition, disorders of tryptophan metabolism
we can synthesize about _____ percent of niacin required each day from amino acid ____________
50, tryptophan
___ mg of tryptophan yields about _ mg of niacin
60, 1
___ mg of tryptophan yields about _ mg of niacin
60, 1
Synthesis of niacin from tryptophan requires what other two vitamins to act as cofactors?
riboflavin and vitamin B-6
list the rda of Niacin for men
16 mg
list the rda of Niacin for women
14 mg
list the dv for niacin
16 mg
list the UL for niacin (nicotinic acid)
35 mg
describe the intakes of niacin by adults
double the RDA, not including the contribution from tryptophan
Which MyPlate section is the best source of niacin?
protein
list food sources of niacin
tuna, fish, poultry, peanuts, cereals, beef, asparagus, coffee, tea
niacin is ____ stable; ______ is lost in cooking
heat, little
list side effects of too much niacin
headache, itching, increased blood flow
what level is too much niacin?
above 100 mg per day.
what parts of the body could be damaged by too much niacin?
gi tract and liver
megadoses of niacin are recommended for what>
cardiovascular disease
what is pantothenic acid required for?
synthesis of coenzyme A
what is coenzyme A?
a coenzyme in chemical reactions that allow the release of energy from carbs, lipids, proteins. it also activates fatty acids
what does pantothen mean in Greek?
from every side
is pantothenic acid deficiency rare?
yes
who might have pantothenic acid deficiency?
those with alcohol use disorders and nutrient-deficient eating patterns.
what is the AI for pantothenic acid?
5 mg
what are the richest sources of pantothenic acid?
every food group, sunflower seeds, mushrooms, peanuts, eggs, meat, milk, vegetables
is there observable toxicity set for pantothenic acid?
no
vitamin b-6 is a family of _______ structurally similar compounds
three
what is the active vitamin B-6 coenzyme?
pyridoxal phosphate
what are the coenzyme forms of b-6 needed for
activity of enzymes involved in carb, protein, lipid metabolism
list symptoms of vitamin b-6 deficiency
depression, vomiting, skin disorders, nerve irritation, anemia, impaired immune response.
athletes may need slightly more ___________ ____ than sedentary adults
vitamin b-6
athletes may need slightly more ___________ ____ than sedentary adults
vitamin b-6
why do athletes need more b-6?
their bodies process large quantities of glycogen and protein
what is the RDA of b-6 for both men and women?
1.3 mg
what is the UL for b-6
100 mg
what is the DV of b-6
1.7 mg
list sources of b-6
animal products, cereals, vegetables, fruits
which section of myplate offers the most b-6
protein
_____ products contain more bioavailable b-6 than _________ products
meat, plant
B-6 is rather ______; ______ and ______ can destroy it
unstable, heating, freezing
describe symptoms of b-6 toxicity
walking difficulties, hand and foot tingling/numbness, skin lesions, photosensitivity, nausea, heartburn.
what does biotin do?
assists in the addition of carbon dioxide to other compounds; important for synthesizing glucose/fatty acids and breaking down amino acids.
list people at risk of biotin deficiency
people with genetic disorders that prevent biotin being released, people with chronic alcohol exposure, pregnant and breastfeeding women
list symptoms of biotin deficiency
loss of hair, scaly skin inflammation, tongue and lip changes, brittle nails, decreased appetite, nausea, vomiting, anemia, depression, muscle pain, poor growth
list the AI and DV for biotin
30 micrograms
is there a UL for biotin?
no
list good sources of biotin
protein, egg yolks, peanuts, cheese
how can we get biotin from eggs?
cooking them
why can we not absorb biotin from raw egg whites?
biotin is abound to avidin which inhibits absorption, cooking denatures avidin
what does iodine do
thyroid hormones are synthesized using iodine and tyrosine.
how does goiter happen?
a person’s iodine intake is insufficient and their thyroid gland enlarges to take up more iodine from the bloodstream
what happens to a woman’s baby if she is iodine-deficient?
the fetus will suffer iodine deficiency; this is known as congenital hypothyroidism
what is the RDA and DV for iodine
150 micrograms
most North Americans consume how much iodine per day?
190-300 micrograms
sea salt and kosher salt are not _______
iodized
what is the UL for iodine
1100 micrograms
what happens if high amounts of iodine are consumed?
thyroid hormone synthesis is limited
what does chromium do?
enhances the function of insulin, metabolism of lipids and proteins
list symptoms of chromium deficiency
impaired blood glucose control, elevated blood cholesterol and triglycerides
list sources of chromium
meat, whole grain products, eggs, mushrooms, nuts, beer, spices, brewer’s yeast
what percentage of chromium is absorbed?
.4-2.5%
how is absorption of chromium enhanced?
vitamin C and niacin
where is chromium stored?
liver, spleen, soft tissue, bone
does a UL for chromium exist?
no
how does chromium toxicity happen?
people exposed to industrial waste, and in painters who use art supplies with high chromium content
what is the DV of chromium
35 micrograms
what are the symptoms of chromium toxicity?
liver damage and lung cancer
what percentage of manganese is found in bone
25-40%
what other mineral does manganese substitute with in metabolic processes
magnesium
what does manganese do?
a cofactor for the synthesis of glucose and metabolism of amino acids
how would manganese deficiency happen in humans
being fed intravenously with solutions without manganese
what happens to animals on manganese-deficient diets?
alterations in brain function, bone formation, and reproduction
list good sources of manganese
nuts, rice, oats, whole grains, beans, leafy vegetables
what is the UL for manganese
11 mg
people with _____ iron stores should avoid ____________ supplements
low, manganese
what does molybdenum do?
metabolism of amino acids that contain sulfur
how can one be molybdenum-deficient
being fed intravenously without molybdenum
describe symptoms of molybdenum deficiency
increased heart/respiratory rates, night blindness, mental confusion, edema, weakness
list good sources of molybdenum
milk and dairy products, beans, whole grains, nuts
what is the RDA and DV of molybdenum
45 micrograms
what is the UL of molybdenum
2000 micrograms
toxicity risk of molybdenum in humans is quite _____
low
what are the symptoms of molybdenum toxicity
weight loss and decreased growth
describe functions of choline
cell membrane formation, nerve function/brain development, lipid transport
list good sources of choline
soybeans, egg yolks, beef, cauliflower, almonds, peanuts.
what is the UL for choline
3500 mg
can choline be synthesized in the body?
yes, by using other nutrients like folate and methionine
how much does the AI for choline during pregnancy and breast feeding increase?
450 mg to 550 mg
what is the AI of choline for men?
550 mg
what is the AI of choline for women?
425 mg
what is the DV of choline?
550 mg
exceeding the choline UL will result in what?
fishy body odor and low blood pressure
