Fat, Carb, Fiber, Water and Micronutrient Requirements during Adulthood Flashcards
1
Q
calcium RDA
A
1000 mg/d in both males and females 12-50
2
Q
calcium based on
A
data showing increase in bone mineral density in women with 1000 mg/d
3
Q
phosphorus occurs as
A
PO4
4
Q
phosphorus needs
A
PL, nucleotides, nucleic acid
- buffers acid or alkali
- maintain pH
- temporary storage and transfer of energy from metabolic fuels
- phosphorylation
5
Q
where is 85% of PO4 found
A
in bone
6
Q
EAR for phosphorus men and women above 19
A
580 mg/day
7
Q
RDA for phosphorus men and women above 19
A
700 mg/day
8
Q
RDA for magnesium for men
A
men 19-30= 400 mg/d
men above 30 = 420 mg/d
9
Q
RDA for magnesium for women
A
19-30 = 310 mg/day
above 30 - 320 mg/d
10
Q
2/3 of iron is in
A
Hb
11
Q
15 % of iron is in
A
myoglobin
12
Q
bioavailability of iron for children >1 year, adolescents, non-prep adults on a typical diet
A
18%
13
Q
iron EAR for iron for men
A
6 mg/d all ages
14
Q
iron EAR for women
A
8.1 mg/day before menopause
15
Q
iron EAR for women after menopause
A
5 mg/d
16
Q
iron RDA for men
A
8 mg/day
17
Q
iron RDA for women before menopause
A
18 mg/day
18
Q
iron. RDA for women after menopause ( 50)
A
8 mg/d ( same as RDA for men)
19
Q
EAR of iron is complicated bc
A
based on need to maintain a normal, functional Fe concentration while only a minimal store of serum ferritin of 15 microgram/L)
20
Q
potassium intake of AI is important bc
A
lower PB
blunt elevated BP relating to salt
reduce kidney stone risk
reduce bone loss
21
Q
AI for potassium
A
4.7 g/d
22
Q
does AI for K increase in activity
A
no stays at 4.7 g/d ( remember that this is g and not mg like in the case of iron, phosphorus, magnesium and calcium
23
Q
AI for sodium
A
1.5 g/d Na
24
Q
1.5 g/d of Na is equal to how much salt
A
3.8 g
25
UL for salt in sedentary adults
2.3 d/g Na, 5.8 g salt
26
is there a Ul for Na in active adults?
NO! must be due to salt excretion
| - there AI also increases to >1.5 g/d ( which depends upon salt loss, but could actually be as high as 10 g/d)
27
why is sulfur important
in a.a's
| in essential components ( glutathione)
28
how do we get sulfur
s-containing aa form protein
29
AI for sulfur
there is currently no intake requirements estabilshed
30
thiamin (B1)
coenzyme in the metabolism of CHO and branched aa
31
req of thiamin is based on
need to achieve and maintain transkelotase activity in RBC, without excess thiamin excretion
32
role of thiamine in CHO metabolism ?
TPP ( a derivative of thiamine) which is needed in PPP, (for transketolase activity in the PPP), to turn pyruvate into acetyl-coA, in the TCA cylcle and to turn branched chain keto acids into branched chain acyl-CoA
33
what is the rationale for the slight adjustment req in men vs women
using less energy and smaller size
34
thiamin RDA men
1.2 mg/d
35
thiamin RDA for women
1.1 mg/d
36
deficiency of thiamine
called beriberi, signs of def only occur with extreme deficency. it affects the heart and circulatory system ( RBC, no regeneration of NADPH from PPP bc no TPP)
37
how do we assess thiamine status?
with RBC transkeloase activity, the concentration of thiamin and the concentration of phosphorylated thiamine esters in the blood, urinary thiamin excretion under basal conditions and after thiamine overload ( high excretion after loading means that the status in adequate)
38
median intake of thiamine in the US /d
is 2 mg/d which is adequate seeing as the RDA is 1.2 mg/d men and 1.1 mg/d women
39
Riboflavin (B2) function
a coenzyme in various oxi-redo reactions - energy production
40
req of riboflavin is based on
1. RBC glutathione reductase activity (glutathione reductase catalyzed the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH))
2. RBC concentration of riboflavin
3. urinary riboflavin excretion
41
where is riboflavin needed?
in glutathione reductase activity (FAD)
42
EAR of riboflavin derived from
signs of deficency, biochemical values, urinary excretion
43
RDA for men (riboflavin)
1.3 mg/d
44
RDA riboflavin for women
1.1 mg/d
45
median intake of riboflavin in US
2 mg/d ( we are getting enough on average)
46
Niacin (B3) function
coenzyme for Hydride ion (H-) transfer by dehydrogenase enzymes, which remove one of more hydrogens from a substrate to an acceptor molecule. niacin may act as a donor or an acceptor for a hydride ion- this is a very common need in many oxi-reduco reactions (fuel oxidation, FA and steroid synth, intracellular respiration )
47
primary criteria for setting niacin requirment
urinary excretion- bc excess is methylated in the liver and then sent to be excreted
48
how is requirement for niacin expressed
```
niacin equivalents (NEs)
- conversion of trypotphan may occur ( wide variation )
```
49
is there an adjustment made for niacin bioavailability
no
50
a deficiency is what may decrease the conversion ration of tryptophan to niacin?
iron, riboflavin, pyridoxine
51
RDA for niacin
16 mg/d men / 14 mg/d women ( there is a higher coefficent of variation (15%)) due to variation in conversion of tryptophan to niacin) - median intake is 41 mg/d
52
B6 (pyridoxine) function
coenzyme in the metabolism of amino acid, glycogen and shingoloid bases (in the brain)
53
primary criterion to estimate RDA of B6 ( pyridoxine)
maintenance of adequate blood 5'pyridoxal phosphate levels
54
RDA for both men and women for B6 (pyridoxine)
1.3 mg/day
55
folate (B9) function
coenzyme in single-carbon transfers in the metabolism of nucleic and amino acids
56
primary criteria for folate RDA estimates
RBC folate, blood homocysteine concentrations and folate concentrations
57
why do we hav DFEs?
dietary folate equivalents (DFEs) which adjust for 50% lower bioavailability of food folate vs folic acid
58
1 microgram of DFE is equal to ?
1 ug of food folate
0. 6 ug of folic acid
0. 5 ug of supplementation on empty stomach
59
RDA of DFE for both men and women
400 ug/day ( folate in men now has role in reproductive health)
60
cobalamin (b12) function
coenzyme for methyl transfers ( homocysteine to methionine and methylmalonyl-coA to succinylcholine -CoA)
61
RDA of b12 based on
maintenance of hematological stats and normal b12 blood values
62
RDA for men and women B12
2.4 ug/d
63
biotin (B7) function
coenzyme in bicarbonate -dependent carboxylation rxns
64
AI for biotin ( B7)
30 ug/day mean and women
65
Choline function
precursor for acetylcholine, PhL, and the methyl donor betaine
66
criteria for RDA for choline
prevention of liver damage as assessed by serum alanine aminotrasferase levels
67
serum alanine aminotransferase is used to detect?
liver damage and set the RDA estimate for choline
68
deficiency of choline leads to
muscle damage and abnormal fat deposits in the liver--> NAFLD, this is bc VLDL require phosphatidylcholine (lecithin) to get packaged and leave the liver
69
choline in the diet
free choline or bound as esters
70
can the body make choline?
yes the demand is modified by methyl-exchange relationships between choline, methionine and folate and B12 --> de nova is not sufiencent
71
AI for choline ( men and women slightly different)
550 mg/d day and from this they extrapolated for women to be 425 mg/d
the only data supporting this is that in men this amount prevents aminotransferase abnormalities --> based on one single study!!! need more info on this
72
Pantothenic acid (B5) function
component of coenzyme A and phosphopantetheine ( FA metabolism )
73
B5 deficiency
rare - only in case of semisynthetic diets or antagonist of the vitamin
74
criterion for B5 AI
adequate intake to replace urinary excretion, basically no evidence suggesting the the current intake of 4-7 mg/d is inadequate so they say the AI is 5 mg/d
75
AI of B5
5mg/d
76
Vitamin C
antioxidant, cofactor for enzyme in the biosynthesis of collagen, carnitine and neurotransmitters
77
RDA of vitamin C based on
intake to maintain near -maximal neutrophil concentration and minimal urinary excretion of ascorbate
78
RDA of vitamin C men
90 mg/d
79
RDA vitamin c women
75 mg/d
80
Vitamin A function
gene expression, growth, eyes, reproduction, immune function
81
preformed vs proformed vitamin A
preformed is animal derived and preformed is plant derived
82
EAR of vitamin A based on
dietary amount to maintain given body-pool size in well nourished subjects - to ensure adequate pool incase increased needs ( stress, low intake)
83
EAR and RDA for men RAE
EAR 625 ug/d RDA 900 ug/d
84
EAR and RDa for RAE for women
500 ug/d and 700 ug/d
85
1 ug of retinol or 1 ug of RAE is equivalent to what amounts of proformed vitamin A??
12 ug b-carotene, 24 a-carotene and 24 b-crytoxanthin
86
Vitamin D function
calcium and PO4 increase absorption in the small intestine, anti-proliferent and pro-differiation effects ( may halt tumor growth)
- some individuals with less sunlight are more prone to certain tumors
87
major physiologically relevant forms of vitamin D
D2 ( ergocalciferol; yeast and plants sterols)
D3 ( cholecalciferol from 7- dehydrocholesterol)
- found naturally in very little foods, but synthesized in the skin
88
evidence suggests that blood concentrations of _____ nmol/L is considered adequate for bone and overall health status
50 nmol/L
89
RDA for vitamin D men and women over 19
600 IU
90
RDA for vit D after 70
800 IU
91
Vitamin E function
unknown metabolic function; antioxidant, stops propagation of lipid peroxide
92
RDA for vit E based on
induced deficiency caused a correlation in H2O2 erythrocyte lysis
- RDA is determined by the level of tocopherol that protects RBC against hemolysis caused by hydrogen peroxide
93
how many major forms of vit E, name them
4; a-tocopherol (trimethyl), b-tocopherol (dimethyl), y-tocopherol (dimethyl but in different positions) and g-tocopherol (monomethyl)
94
are the forms interconvertible in humans?
no
95
describe the structure of tocopherols
a substituted hydroxylated ring system (chromanol ring) with a long, saturated ( phytol) she chain--> RRR stereochemistry is present in the side chain in nature, due to the presence of the methyl group on the same right side of the moleucle
96
difference between tocopherols and toctrienols
tocopherols have a saturated phytol chain whereas the tocotrienes are unsaturated
97
how many possible stereoisomers of tocopherols?
3 asymmetric carbons --> so 2^3 = 8 , these are not treats equally in the human body ! the activity of a synthetic racemic inure is less than the same number of molecules consumed from food
98
vitamin E supplement derived from "natural sources of vitamin E" is??
RRR-a- tocopherol
99
DRI definition limited to @R stereoisomeric forms, meaning?
RRR, RSR, RRS, RSS-a tocopherol
| - mean the first carbon has to be in the R position ( this is carbon #2)
100
All rac-a-tocopherol supplements contain?
1/2 the activity of RRR a-tocopherols or 1/2 the activity of other 2R forms
-- so in appling this, since the RDA is 15 mg/d of a-tocopherol, one would have to consume 30 mg/d of all rac-a-tocopherol supplements ( bc supplemts are assumed to half equal amounts of all possible stereoisomers)
101
plasma vitamin E concentration is dependent on
the affinity of hepatic a-tocopherol transfer protein (a-TTP)
102
highest affinity with hepatic a-TTP in which stereoisomer?
RRR, which is maintained in the human plasma, the synthetic forms SRR are efficiently absorbed but not well packaged into lipoproteins bc poor affinity to TTP
103
which stereoisomers fail to bind to TTP and cannot be included in the requiremtn
2S ( S in position 1, carbon #2) and tocotrienols and other tocopherols ( B, Y, g)
104
do the other tocopherols (B, y, g ) bind with a-TTP?
no, so they cannot be considered in the requirement
105
EAR and RDA and AI for vitamin E apply only to ?
2R-stereoisomers, however most nutrient data bases and nutrition labels no distinction
106
RDA for men and women
15 mg/day of a-tocopherols
107
Vitamin K function
coenzyme during synthesis of biologically active form of a number of proteins involved in blood coagualation and bone metabolism
108
AI for vitamin K based on
healthy individuals intake
| 120 ug/day men and 90 ug/day women
109
major form of vitamin K in the diet
phylloquinone
110
what are menaquinone?
form of vitamin K that are produced by bacteria in the lower bowel
111
AI for vitamin K
120 ug/day for men and 90 ug/day women and pregnant women
