Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Yr 1 Nutrition Vits and Mins Lecture > Vits and Mins Lecture Dec 2017 > Flashcards

Vits and Mins Lecture Dec 2017 Flashcards

1
Q

What is the definition of a mineral?

Can the body synthesis minerals?

A

A naturally occurring INORGANIC substance with its own crystalline structure.
It is solid and in different colors
No - have to be eaten daily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What Vitamins and minerals do humans need and what are they used for in the body?

A

B1, 2, 3, 5, 6, 7, 9 and 12
Ca, Mg, Zn, P, K Na and Cl
Used for energy production and other metabolic actions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is bio availability?

A

Absorption of a mineral AFTER digestion from food and BEFORE its use in tissues and cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What can affect bio availability?

A

Body mineral status (eg, deficiency increases abs)
Substances present in foods (phytates, Vit C etc)
Other minerals present in food (eg Zn abs reduced by Fe supps)
Disease states
High concentration of one mineral in the intestine (eg, excess Ca binds to P)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define ‘sub clinical insufficiency’

A

Reduction in nutrient stores with no symptoms. Reduction of enzyme activity (lack of coenzymes) Adverse behavioural effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define end-stage nutrient inadequacy

A

Classical deficiency syndromes

Terminal tissue pathology

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Name 5 other metabolic reactions that involve minerals

A 
Bone mineral density 
Muscle contractions
Bone health and osteoporosis
High BP
T2DM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

B7 - Biotin - where is B7 aborbed and stored

A

Absorbed in small intestine and uses a sodium dependent transporter.
It is stored in the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is B7 involved in within the body

A

B7 is a coenzyme. Enzymes containing B7 are involed in gluconeogenisis, propionate metabolism & fatty acid synthesis
Also growth, development and energy production
***B7 main role - synergy with other Vits and Mins and support of Kreb cycle activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What organ has the highest concentration of B7

A

The brain (50 x higher than plasma)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name some food sources for B7

A 
Bean Sprouts
Bulgar Wheat
Egg Yolk
Kidney (high)
Liver (high)
Oats
Wholegrain cereals
Leafy greens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is there a recognised RDA for B7

A

Currently no. AI for an adult is 35-40ug/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is B7 bound to, where is it absorbed and where is it stored

A

It is bound to protein, which is metabolised in the intestines to yield FREE BIOTIN - absorbed then in SI
and stored in the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What can impair absorption of B7

What can enhance absorption of B7

A

Chronic alcohol intake
Raw egg whites (avidin can bind biotin)
Cooked eggs are fine though

Colon absorption may be enhanced by the effects of a vegetarian diet on gut flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What skin conditions has B7 been shown to help in

A

Cradle cap
Seborrheic dermatitis
no evidence that supplementation will help
Brittle nails
Diabetes(may lower Haemoglobin A1c - marker of long term blood sugar levels)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Who are are risk of B7 deficiency

A

Deficiency is unknown except in parenteral nutrition and the consumption of LARGE amounts of egg whites uncooked.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Name 6 deficiency symptoms of B7

A 
Scaly and seborrheic dermatitis
Hair loss
Nausea
Depression 
Burning/itching sensations
Glossitis (red tongue)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What can affect a persons individual requirement of B7

A 
B7 is B5 and Na+ dependent
B7 - shown to be an intestinal bacterial source
Long term AB use could decrease B7 available from gut bacteria
Elderly (poor gut function)
Pregnancy (need for more - rapid growth)
Smoking - increases catabolism
GIT diseases ie Crohn's, colitis, IBD
T2DM
Heavy alcohol intake
Raw egg whites (avidin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Name 3 meds that B7 can interact with

Are there any cases of toxicity

A

Antibiotics
Carbamazepine
Isotretinoin
There are no known cases of B7 excess leading to toxicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How many types of folate are there

A

There are 2 types:
Folate from food
Oxidised monoglutamate form used in supps
folate is the generic term describing both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are B9’s main functions

A

Coenzyme for single carbon transfers in synthesis of nucleic acid and metabolism of AA’s
The conversion of homocysteine to methionine
Cell division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Where is B9 absorbed and stored

A

Food sources are hydrolised to monoglutamate form in gut then absorbed by active trans across intestinal mucosa
Stored in the liver (metabolised) with unmetabolised amounts in blood and tissues
THF - tetrahydrofolate) active in metabolic reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Does folic acid occur naturally

A

No. Folic acid is the synthetic form found in supps
Synthetic folate is more bioavailable than food folate
Folate unstable after heating 60 degress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Briefly explain what is meant by ‘the folate trap’

A

After absorption a methyl group is added to folate and then delivered into the cells
In order for folate to function the methly group must then be removed by an enzyme that requires B12
WITHOUT THAT HELP FOLATE iGETS TRAPPED inside the cell in it’s methyl form unable to do its job - DNA synthesis and cell growth impaired (metabolic situation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Name some sources of B9
``` Abundant in foods of plant origin (foliage) Green leafy veg richest source Legumes Citrus fruit Live Spinach Red Kidney beans Broccoli Asparagus ```
26
What is the adult RDA and what are the supplement ranges for B9
RDA 330ugDFE/day Supp range - 1000-5000mcg (as folic acid) TUI for adults is 1000ug/day ****400mcg recommended during preconception and first trimester****
27
Why is folate supplementation recommended pre-conception and during 1st trimester
Taken preconceptionally folic acid has been shown to prevent neural tube defect such as spina bifida 400ug BEFORE CONCEPTION as closure of neural tube takes place on day 28 of pregnancy before woman knows she is pregnant
28
What can destroy folate in foods and where is it absorbed
Heat and oxidation in cooking and storage can destroy up to 50%. Absorbed in SI
29
Is the bio availability from food as good as that from supplements for B9
No. It is approx 80% of that from supps (higher than previously thought)
30
What can B9 be used for therapeutically
Lowering homocyteine - this also reduces progression of atherosclerosis and improves arterial blood flow 300mcg dietary folate associated with lower risk of stroke and CV disease Dietary folate seems to reduce risk of breast cancer Supplementing alongside antidepressants may improve treatment response Vitiligo - needs medical supervision
31
Name two functions that are impaired by B9 deficiency
Cell division | Protein sythesis
32
In B9 deficiency what type of cells are affected first and what does this mean for the body
Fast dividing cells affected first - RBC's and GIT cells This results in Megaloblastic anaemia and GIT deterioration - GIT deterioration can be triggered by alcohol abuse= increased folate loss from the body = further GIT weakening and folate loss (viscous cycle)
33
What can high levels of homocysteine indicate in the body
Could indicate B9 insufficiency (because body unable to convert homo to methionine) BUT this is not always the case - B12 could also mask this situation
34
What are insufficient levels of folate in pregnancy a risk of
Neural tube defects and foetal growth retardation
35
Name 5 things other than pregnancy and high alcohol intake that can affect individual requirements of B9
Cancer Chickenpox/measles Burns Blood loss
36
Name 3 medications that may interact with B9 | Is B9 toxic?
Antacids Aspirin Diuretics Folate in foods shows no sign of toxicity Excess folic acid has been linked to Zn impairement in the past. No recent studies available
37
Name the 5 different types of Vit B12
Methylcobalamin - most active Hydroxycobalamin - created by bacteria in gut naturally and easily converted Cyanocobalamin - synthetic version Adenosylocobalamin - occurs during Krebs Cycle Aquacobalamin - precursor of adeno and methyl
38
What is B12's primary role
It is a one carbon (methyl) donor which facilitates metabolism of folic acid and synthesis of DNA
39
How is B12 released in the stomach, what is it combined with and where is it absorbed
B12 is protein bound and released by HCI and gastric protease. It is combined with IF (glycoprotein) found in parietal cells Absorbed in the terminal ileum
40
Do high levels of IF increase or decrease Vit B12 absorption
Decrease it
41
What role does B12 play in the nervous system
B12 plays a role in the sythesis of myelin. If levels of B12 decrease this results in abnormal levels of MMA that can lead to defective nerve transmission
42
Can humans synthesis their own B12
Yes from bacteria but it is not absorbed
43
B12 on foods are through......
Bacterial synthesis or contamination
44
What animal sources provide B12
Only found in foods of animal sources (where it originates from the ingestion of bacterial-contaminated food) Sources include - Meat (liver good) Fish, Eggs, Milk and Cheese
45
What is the EU AI set at for adults for B12
19-50 yoa 4ug/day | Supplement range is 300-8000ug/day
46
How does cooking affect B12
As B12 is found in food bound to protein so 70% of its activity is retained during cooking However, large amounts lost in pasteurised or evaporated milk
47
Explain the steps of absorption of B12
1 Must be released from protein in stomach by pepsin digestion 2 Combines with R-protein moving into duodenum 3 Released from R-protein there and binds to IF (IF can only bind cobalamins mentioned earlier) 4 The IF-Vit B12 complex then absorbed in distal ileum
48
Where is most Vit B12 stored and approx how much is there in mcg's in an adequately nourished person
In the liver - about 2000mcg (a store of 5-7 years!)
49
Who may need extra B12 for specific therapeutics
Elderly - those who take B12 orally are more likely to have NORMAL B12 levels than those who do not B12 + B9 and B6 = can reduce serum homocysteine
50
Does supplementing with B12 B6 and B9 therefore prevent death or CV events such as stroke?
Whilst this complex can reduce total homocysteine it does NOT help prevention of death or CV events such as stoke
51
What other group of people may need B12 supplementation
``` Vegans In pregnancy Thyrotoxosis Malignancy Liver/Kidney disease ```
52
Name 5 signs of insufficiency and 5 signs of deficiency for B12
Insuff - Fatigue, weakness, No appetite, Mego anaemia, tingling in hand and/or feet Def - Difficulty maintaining balance, confusion, dementia, poor memory, nerve damage
53
What factors may effect individual requirements and what is the toxicity level associated with B12
Malabsorption of B12 due to low IF levels could lead to pernicious anaemia (presenting like megalo anaemia) Age related degen of gastric cells = less IF Hereditary deficiency of IF Autoimmune destruction of IF Crohns, IBD Unhealthy vegans/veggies B12 is NON TOXIC from foods and as is water soluble neither is supplementing (no upper limit has been defined due to its safety)
54
Name 2 meds that can inhibit B12 absorption
Metformin and PPI's
55
What are the 2 forms of Vit C called
L-Ascorbic acid | Dehydroascorbic acid - an oxidised form of ascorbic acid
56
Is Vit C fat or water soluble and where can it be found in the body
Water soluble found in most tissues in the body
57
Can humans synthesis C
No, we have lost the ability to do so
58
What are the names of the transporters that import ascorbate over and into the plasma membrane and absorb it in the distal ileum
SVCT - sodium ascorbate C-transporters and GLUT - hexose transporters NOTE - SVCT2 is the only one that facilitates ascorbic acid into almost every tissue except RBC's
59
What are the functions of C
Ascorbate presents electrons for essential enzyme reactions which are primary antioxidant scavenging radicals found in plasma or cells Vit C is also used for biosynthesis of: Collagen, Protein metabolism, Neurotransmitters (conversion of tryptophan to tyrosine) Thyroxine synthesis Adrenal steroid hormone synthesis
60
How does Vit C increase Fe absorption thus keeping Fe bioavailable
C increases iron absorption (non-heme) by protecting it from oxidation and enhancing intestinal absorption by keeping it in its Fe2+ form (Fe3+ form is not bioavailable)
61
What is the term used for the oxidation of organic substrate by Fe and why is C involved in this process
The term used for oxidation of inorganic substrates by Fe is the Fenton Reaction. C is involved because ascorbic acid can recyle Fe3+ and Fe2+
62
Where is C stored in the body
There are no specific storage sites for C but adrenals, pituitary gland and WBC's appear to have highest concentrations
63
What are the best sources of C from food
``` Blackcurrants, Redcurrants Citrus fruits Strawbs, Blacks, Blues Kale, Rocket Watercress Peppers ```
64
What can cause significant losses to C in food
When the veg wilts or when it is cut (releasing ascorbate oxidase from plant tissue) Leaching into water Atmospheric oxidation when foods are left to stand before serving
65
What is the RDA for male and female adult What is the supplement range
PRI's - F 80mg pe day, male 110mg/day 250-10,000mg British recommendation for RNI is currently 40mg
66
What can be done to foods containing C to help retain the vitamin
Refrigeration and quick freezing | Most frozen foods have higher levels of C than fresh
67
Where is C absorbed
Both ascorbic acid and dehydroascorbic acid are absorbed in the mouth and SI
68
What happens to unabsorbed ascorbate
Unabsorbed ascorbate from high doses is a substrate for intestinal bacteria metabolism causing GIT discomfort and diarrhoea
69
What transports C into the cells
Glucose transporters
70
What happens to the process of C by glucose transporter in a person with high blood glucose (diabetic)
Vit C uptake is significantly inhibited
71
What can C be used for in specific therapeutics
``` AMD (age related macular degeneration) Albuminuria Atherosclerosis Cancer - dietary Vit C might decrease mouth and some other cancers Gallbladder disease H Pylori Osteoarthritis Sunburn ```
72
Insufficiency - What could increase a persons need for C
Burns Infections Certain meds (Aspirin, oral contraceptives) Smokers (inc passive) - increased oxidative stress Anyone on limited eating regime Malabsorption and GIT disease Immune issues (recurring infections and colds)
73
Deficiency - What are the symptoms of C
``` Scurvy Muscle loss Rough dark brown scaly skin wounds that do not heal bone fractures due to not healing ```
74
What factors can affect individual requirements Is Vit C toxic
Excess blood glucose can inhibit C uptake = oxidative stress Cancer treatment CV disease At high levels (3000mg/day) can result in diarrhoea, ab cramps and nausea Long term high dosage C supplementation can adversely affect people with Fe overload (Fe induced free radicals) C would therefore be a pro-oxidant

Yr 1 Nutrition Vits and Mins Lecture (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions