Vitamins - B Flashcards
Name of B1
Thiamine
Name of B2
Riboflavin
Name of B3
Niacin
Name of B5
Pantothenic acid
Name of B6
Pyridoxine
Name of B7/8
Biotin
Name of B9
Folate
Name of B12
Cobalamin
Different chemical forms of each vitamin exist, what are they called ?
Vitamers
They are similar in structure meaning a person deficient in B3 can be relieved with either vitamer niacinamide or nicotinic acid
List four functions of vitamins
support the immune system
regulating gene expression
supporting neurological activity
Facilitating ATP production
Manufacturing of blood cells
Regulation of hormones
The body cannot produce vitamins, with the exception of
Vitamin D
Provide an example of vitamins acting as co-factors
B vitamins are vital co-factors for the action of the CYP450 enzyme system needed for phase 1 liver detoxification
Define vitamin insufficiency
sub clinical deficiency (vague symptoms
Define vitamin deficiency
clinical - signs and symptoms of deficiency
Name/list the 5 stages of progression of insufficiency to deficiency of vitamins
- preliminary reduction of stores
- reduction in enzyme activity
- physiological impairment (signs/symptoms)
- classical deficiency syndromes
- Terminal tissue pathology
True vitamin deficiencies are rare except
D and B12
Name the active form of B1 and the mineral needed for conversion
Thiamine phyrophosphate (TPP)
How long can the body store B1
1 month
How is B1 content reduced, how is it best consumed and what impairs absorption
Boiling and freezing - 50%
toasting - 30%
BEST CONSUMED RAW
Absorption impaired by alcohol, tea, coffee, PCP, stress, antacids
Name 4 four food sources of B1
Yeast extract
Peas
Oranges
Nuts
Sunfower seeds
Whole grains
List the functions of B1 and therapeutic uses
ATP production: fat, protein and carb metabolism; formation of acetyl CoA
Therapeutic use: fatigue, energy production, fertility
Nervous system functioning: the aa metabolised by thiamine can be used to create neurotransmitters, eg GABA
Therapeutic use: cognitive decline, low mood, parkinsons, nerve repair
what are the dietary requirements of B1
The more carbs, eat, the more B1 needed (metabolism to create ATP)
0.4-0.5 mg / 1000 kcal
B vitamins work ______ and are often found _______ in nature
synergistically
together
What are the symptoms of subclinical deficiency and who is most likely to be depleted
Depression, irritability, fatigue, muscle weakness, memory loss, cramp, GIT disturbance.
The elderly.
What B vitamins are responsible for energy production
1, 2, 3, 12
What is distinctive about B2/riboflavin and turns urine yellow when consumed over what amount
fluorescent green/yellow compound
Over 27mg per day in supplement
What food sources is B2/riboflavin found and what reduces its value
Spinach, wild salmon, mushrooms, yeast extract, almonds, quinoa, lentils, organic eggs, meat.
Sensitive to light, and nutrient value reduced by heating and freezing.
Name three functions of B2 riboflavin
Energy production: carb/fat/protein metabolism. Krebs cycle/ Needed for FAD.
Liver detoxification - regeneration of glutathione/CYP450 enzymes
Iron metabolism
Name therapeutic uses for B2/riboflavin
anaemia
detox programme
fatigue, migraines (400mg per day)
stress
What is the maximum absorption value of B2/riboflavin
what supports absorption
what impairs absorption
27mg/day single dose
Bile salts
alcohol, antacids
What impairs the BIOAVAILABILITY of B2/riobflavin
copper, zinc, caffeine, saccharin, theophyline (in chocolate)
What increases the need for B2/riboflavin
smoking reduces levels
exercise
pregnancy
aging
What is the recommended dose of B2/riboflavin
90-400mg/day split through day
Name 3 signs of poor intake of B2/riboflavin
sores in mouth corners
red, dry, atrophic tongue
scaly dermatitis (esp around mouth, nose, eyes, ears)
red, tired, gritty eyes,
Fatigue
Deficiency - alopecia
What amino acid is B3 synthesised from in the body
tryptophan - 60mg produces 1 mg niacin
When does B3 become essential
when tryptophan metabolism is altered
What are the active forms of niacin/B3
NAD and NADP - energy carrying molecules
What are the two compounds with niacin activity
nicotinic acid
nicotinamide
Name food sources of B3
Yeast extract
mushroom
green leafy veg
salmon
sunflower seeds
avocado
peanuts
meat and poultry
How are recommendations for B3 stated
as niacin equivalents (NE). Equal to the total niacin compounds in food 1/60th of the tryptophan content of the food (ie 60mg tryptophan, body produces 1mg B3)
What co-factors are required to synthesise B3 from tryptophan
B2, B6, iron
what is a niacin flush
skin flush/itch due to supplementation. Avoid by using initial dose of 25mg with 1g vit C
Where is B3 absorbed and stored
Small intestine
liver, heart, muscles and kidney
Name the three functions of B3
energy production (NAD/NADP for stages of aerobic respiration)
Cardiovascular - lowers secretion of LDL
Insulin - glucose tolerance factor (GTF). important for insulin response.
Name therapeutic uses for B3
fatigue, alzheimers, hyperlipidaemia, insulin resistance
What are the signs of B3 deficiency
Severe: “pellagra” 4 Ds: diarrhoea, dermatitis, dementia, death. Crohns can cause. Treated with up to 500mg B3 daily by Dr.
Mild: unrelenting fatigue, vomiting, depression, canker sores, sensitive to strong light
What condition can be made worse by B3 supplementation
Gout - urate competes with niacin for excretion
What are the signs of B3 toxicity
hypotension, hyperuricaemia, flush, hypothyroidism
What B vitamin is needed to make coenzyme A (CoA), which goes on to form acetyl-CoA
B5 pantothenic acid
Name food sources of B5
In almost all foods, but richest sources include shiitake mushrooms, avocados, nuts, seeds, fish, meat
What is needed to synthesise B5
intestinal bacteria - therefore antibiotics may reduce absorption
What cooking processes destroys B5
cooking , freezing, processing - up to 80% loss
Name 4 functions of B5
- Energy production (metabolise fats/carb/protein; Acetyl CoA formation)
- Fat metabolism (fatty acid degradation and synthesis)
- Stress hormones (co factor)
- Anti histamine
Name therapeutic uses of B5
fatigue
Acne vulgaris
adrenal fatigue
Hayfever
What might cause depletion of B5 (toxicity rare) and what are the symptoms
alcohol, stress, surgery
Burning sensation in feet and tender heels, fatigue, abdominal distress
Name the two active forms of B6
Pyridoxal 5’-phosphate (PLP)
Pryridoxamine 5’phosphate (P5P)
Name food sources of B6
widely distributed
whole grains
green veg
sunflower seeds
pistachios
walnuts
bananas
lentils
avocados
meat, fish
What percentage of B6 is bioavailable and what synthesises it
75%
Intestinal flora
What reduces B6
processing, preserving, heating, light
What increases B6 requirements
excess alcohol
OCP
GIT issues
Name four functions of B6
Neurotransmitter production - synthesis of GABA, dopamine, Noradrenaline, serotonin
Red blood cell formation - harm production
Methylation - lowers homocysteine
Energy production - aa metabolism, releases stored glucose
Name four therapeutic uses of B6
GIT motility/carpal tunnel/morning sickness
Anaemia
CV disease
Fatigue
What lifestyle factors increase the need for B6
alcohol dependence
high stress
pregnancy hormonal imbalance
Name symptoms of B6b deficiency and state it if is common or rare
Rare, occurs with other deficiencies.
Poor metabolism of fatty acids, leading to skin lesions, dermatitis. Tongue inflammation, mouth ulcers, sores in corner of mouth, PMS, anaemia, drepression
Do drugs deplete B6. Name one in particular affected by B6
Yes, therefore intake should be increased, eg antibiotics, chemo, OCP.
Levodopa - Parkinsons drug) is broken down by B6 therefore should not be supplemented.
Can B6 become toxic
Long term supplementation of 100-200mg/day can lead to neuropathy, acne, headache
List key functions of minerals
Support immune system
Regulate gene expression
Support neurological activity
Facilitate ATP production
Manufacture blood cells
Regulate hormones
Compare fat and water soluble vitamins
Fat soluble:
ADEK
Soluble in fat
can be stored more readily
absorbed in SI into lymphatic system and then into blood
Water soluble:
B and C
Absorbed directly into blood
Storage in minimal except B12
Easily excreted
Name the vitamins of Vitamin A
Retinol, retinal, retinoic acid
What is retinol oxidised to
Retinol to Retinal to retinoic acid
What is the key function of each vitamin A vitamer
Retinol: health of retina
Retinal: Vision (rod and cone cells)
Retinoic acid: Growth and differentiation of epithelial cells
Name the two forms of vitamin A, whether they are active and the main food group they can be found in
Pro-vitamin A: can be converted into retinol in the SI and liver.
Carotenes/carotenoids. The most active carotenes are alpha, beta and gamma and crytpoxanthin
Pre-formed vitamin A: ACTIVE, the body can use it. Found in animal foods
List the main food sources of Pro-vitamin A
Dark green, yellow, orange veg and fruit. carrots, squash, mango, spinach, sweet spud
List the main sources of pre-formed vitamin A
liver, fish liver oils, egg yolk, mackerel, salmon
Summarise the absorption of PRO-VITAMIN A
carotenes are converted to vitamin A only as needed.
5-60% absorption
Fats aid absorption (eg coconut oil)
Cooking/lightly steaming liberates carotenoids from cells
Name the enzyme that converts carotenoids to retinal
BC01 gene. Subject to much genetic variation.
What might reduce the conversion of carotenoids to retinal in the intestinal epithelium and liver
Hyperlipidaemia, liver disorder, diabetes, hypothyroidism
What is the rate of absorption of PRE-FORMED vitamin A
70-90% - therefore animal food can lead to vit A toxicity
What is the recommended maximum dose of Vit A
3000 mcg
higher doses are appropriate for short term only
How is supplementation of vitamin A expressed
As retinol activity equivalents (RAE)
2mcg beta carotene = 1mcg retinol
Because provitamin A (Carotenes) don’t have the same Vitamin A activity as preformed vitamin A
List functions of Vitamin A
VISION AND EYE HEALTH - required for rhodopsin, the light sensitive protein giving the msg of sight.
IMMUNITY - T cell proliferation and interleukin 2 secretion.
Support 1st line of immune defence
GENE EXPRESSION AND CELL DIFFERENTIATION - control of cell differentiation and turnover, regulate expression of over 500 genes
gene expression
normal development of bones teeth and skin
REPRODUCTION - spermatogenesis and egg dev. and implantation
ANTIOXIDANT
List therapeutic uses of vitamin A
recurrent infections
night blindness
visual loss
senile cataracts
acne
hair loss
osteoarthritis
infertility
cancer and disease prevention
list deficiency sign and symptoms of Vit A deficiency
vision impairment at night is early sign
Hyperkeratosis of skin of upper arm
reduced skin integrity
poor taste/smell
recurrent infections
Factors affecting individual requirement for Vit A
DM, thyroid, liver disease
alcoholism
zinc deficiency
Poor gut health
What drug does vitamin A interact wtih
Warfarin as it decreases vit K absorption
What are the two types of vitamin D and name the active form of vitamin D
Ergocalciferol D2 - plants et mushrooms
Cholecalciferol D3 animal source eg sardines, cod liver oil.
BOTH MUST BE CONVERTED TO ACTIVE FORM - CALCITRIOL VIA LIVER THEN KIDNEY
What is the optimal range of vitamin D
75-125 mol/L
How long can vit D be stored in the liver
4 months
For profound deficiency of vitamin D, what dosage would be prescribed
50,000 Iu D3 orally once weekly for 2-3 months or 3 times weekly for one month
What is the key function of vitamin D
to maintain serum calcium and phosphorus homeostasis (heart and nervous system functioning)
vitamin D actions are mediated through a nuclear transcription factor which is present in each cell. It is called…
Vitamin D Receptor (VDR)
It directly or indirectly regulates 100-1250 genes
List the key functions of vitamin D
BONE HEALTH supports bone density
IMMUNE FUNCTION AND REGULATION enhance innate immune system, regulate T helper cells, antibacterial
GIT HEALTH VDR helps regulate mucosal inflammation. Role in commensal bacterial colonisation. stabilises tight junctions
ANTI CANCER - enhances anti tumour activity of innate immune cells. Inhibits angiogenesis
INSULIN - activates transcription of the insulin gene and increases cellular sensitivity to insulin
List therapeutic uses of vit D
osteoporosis
osteomalacia
allergies
autoimmunity
infections
muscoskeletal pain reduction
INtestinal inflammation
cancer prevention
T1DM T2DM
What vitamin must D be balanced with for proper gene transcription
A
From a disease prevention approach, maintaining healthy levels of Vit A and D is crucial for correct gene expression. Explain why
Retinoid X Receptor (RXR) is a nuclear receptor that is activated by vitamin A. Together with VDR is forms a complex with DNA for transcription
List Vit D deficiency symptoms
rickets and osteomalacia
Osteoporosis
severe asthma in children
poor immunity
non specific muscoskeletal pain and fatigue
What are the causes of vitamin D deficiency
low sun exposure
excessive animal protein or Ca intake
lack of dietary fats
impaired liver functionality
elderly
poor intestinal absorption
What drug interacts with Vitamin D
osteomalacia risk increased with use of barbiturates and anticonvulsants
Name the two families of fat soluble compounds with vitamin E activity, and name which is recognised for human nutrition
Tocotrienols
a-tocopherol for nutrition
All have alpha beta gamma delta forms and exist in natural food
How well does vitamin E tolerate heating and freezing
80% destroyed by freezing
30% destroyed by heating
What foods are best for vitamin E
raw and fresh
sunflower seeds
almonds, pine nuts, Oliver oil, avocado, sweet spud, spinach
What organ takes-up Vitamin E and what does it do with it and where is it stored
the liver takes-up all forms of Vitamin E and preferentially secretes a-tocopherol into circulation WITHIN lipoproteins.
Circulated everywhere and stored in adipose tissue
Why do PUFAs increase the requirement for vitamin E
Because of Vitamin E’s antioxidant properties which protect the fatty acid double bonds from oxidation
List the functions of Vitamin E
ANTIOXIDANT - protects the following from oxidation:
- PUFA cell membranes
- Nerve sheaths
- Cholesterol (decreases LDL oxidation)
Chain breaking antioxidant/
Vitamin C and selenium rejuvenate oxidised vitamin E
IMMUNITY - increases phagocyte activity, Differentiation of immature T cells in the thymus
ANTI-COAGULANT
ENDOCRINE
improves insulin action
Modulates oestrogen receptors
SKIN REPAIR
topical use.
List therapeutic uses of vitamin E
scarring, acne
Cardiovascular, atherosclerosis
Male fertility
Menopause
Cognitive decline
Anti-cancer
HIV/AIDS
infections
DM
What are the three types of compound that have vitamin K activity - name them and their sources
K1: leafy green veg. Make-up 80-90% of daily intake. Must be converted to K2
K2: synthesised by bacteria, found in fermented foods. Probiotics support intestinal production, making up around 10%. Synthesis in jejunum and ileum
K3: potentially toxic, synthetic form used in livestock
What are the richest food sources of vitamin K
Nato and dark green leafy veg. Best with dietary fat eg olive oil
What is the optimal intake of Vitamin K300-500 MCG/DAY
300-500 MCG/DAY
What reduces the absorption of vitamin K
High vitamin a intake, aspirin. Low bile secretion, poor fat absorption
List the functions of vitamin K
Blood clotting - required for formation of 4/13 clotting factors
Bone mineralisation - Osteocalcin requires K for synthesis
Is B7/biotin toxic
B7 has no known toxicities
What foods are high in biotin
Egg YOLK (raw whites make biotin unabsorbable), yeast, whole grains, cauliflower, sweet potato, nuts, meat, oily fish
List the two functions of biotin
Gene regulation - regulate gene expression which are critical for metabolism. Particularly supportive of rapidly regenerating tissues, eg skin, hair and nails
Blood Sugar Regulation - in combo with chromium it can improve blood glucose control
List therapeutic uses of biotin
dandruff, brittle nails, dry brittle hair, cradle cap
DM
PCOS
What are the symptoms of biotin deficiency
dermatitis, dry scaly flaky skin, smooth pale tongue, hair thinning and loss, depigmentation
What is the active form of B9/folate
THF - tetrahydrofolate
What is folic acid
a synthetic supplement or fortification form not found in nature
List food sources of folate
Leafy greens, asparagus , avocado, brussels, legumes, citrus, liver
What does folate require for absorption and what happens to it after absorption
pancreatic enzymes
Once absorbed, a methyl group (-CH3) is added and it’s delivered to body cells
What is the ‘folate trap’
B12enzyme removes the methyl group, without this the folate becomes trapped inside cells in its methyl form unable to perform its main functions (DNA SYNTHESIS AND GROWTH)
Where is folate stored
50% liver
What vitamin supplement has the most drug interactions
folic acid
Why have Dietary folate equivalents (DFA) been developed
because bioavailability of folate varies in food compared to supplements
Folic acid is 1.7 times more available than dietary folate - why is this problematic
it is less regulated and absorption is uncontrolled in the body
What is an adverse effect of high folic acid supplementation
nausea
list the functions of folate
Embryo health = healthy development of neural tube
Formation of RBC - without folate erythrocytes are large and immature
Cardiovascular health - methylation of homocysteine to methionine
List therapeutic uses of folate
atherosclerosis
alzheimers
anaemia
prevent spina bifida
What are the signs and symptoms of B9 deficiency
affects rapidly dividing cell types - GIT and blood cells, skin and digestive issues, megaloblastic anaemia.
What factors can cause folate deficiency
alcoholism, OCP, aspirin use, old age.
What two specific medications should you be wary of when using B9/folate
anticonvulsants
methotrexate
What dosage of folate is recommended for preconception./conception
600mcg/day
Why is better to consider using naturally occurring folates
folic acid can mask megaloblastic anaemia of B12 deficiency and may hasten nerve damage. Test B12 to combat.
people with MTHFR may be more susceptible to issues arising from supplementation.
Vitamin B12, cobalamin compounds, contain what essential mineral
Cobalt, it’s in the centre
What are the names of the most active forms of B12
METHYLcobalamin
HYDROXOcobalamin
ADENOSYL cobalamin
CYANOcobalamin
how is B12 synthesised
by bacteria - but not all is absorbed. Any B12 in animal based foods originates from their ingestion of bacterial contaminated feed
How long does B12 storage last in the liver
3-5 years
Name vegan sources of B12
Chlorella pyrenoidosa
korean purple laver
Nutritional yeast
Nori
Shiitake and lions mane
Name animal sources of B12
Meat, liver, milk, cottage and feta, eggs, fish
List the functions of B12
Nervous system - myelin production; neurotransmitter production (dopamine/serotonin); choline (key for brain function)
Erythropoiesis
Methylation - homocystiene to methionine
Energy production - from fats and proteins
List therapeutic uses of B12
MS
Tingling/pins and needles
Sciatica
Megaloblastic anaemia
CV disease
Alzheimers
Fatigue
What are the causes of B12 deficiency
Poor nutrition
GIT/malabsorption (eg lack of intrinsic factor/HCl/coeliac
If good diet intake but deficient, would highlight methylation issue of absorption
What is the most common cause of B12 deficiency
PERNICIOUS ANAEMIA - a malabsorption issue due to lack of intrinsic factor production. Or Helicobacter pylori infection
Pernicious anaemia - autoimmune attack on parietal cells in the stomach (that synthesise IF)
What are the signs and symptoms of B12 deficiency
Megaloblastic anaemia - fatigue, pallor
Neurological abnormalities - tingling/numbness
What is an accurate means of testing B12
test methylmalonic acid (serum or urine testing) - it indicates how B12 is used in cell metabolism.
Is B12 considered toxic
no - it’s’ one of the safest vitamins
What drug interactions are there with B12
OCP, alcohol excess, PPI lower B12 levels
Ca may enhance absorption
Who is most at risk of pernicious anaemia
those with autoimmune disease
