8. VITAMINS Flashcards
This module covers: • Specific characteristics of vitamins A, C, D, E, K and the B vitamins. • Dietary sources, bioavailability and interactions. • Functions, deficiency states, therapeutic uses and safety considerations. • Dosage levels and preferred forms for micronutrients. (186 cards)
1
Q
What are vitamins? How does the word vitamin break down and who coined the term?
A
Vitamins are carbon-containing compounds that are essential to the body in small amounts for normal growth and function.
“Vita” = life
“Amine” = contains nitrogen
Biochemist Casimir Funk
2
Q
What led biochemist Casimir Funk to the discovery of vitamins?
A
He discovered ‘beriberi’, which causes mostly neurological symptoms such as numbness and mostly affects those on a diet of white rice. Funk identified that the cause was a lack of thiamine (vitamin B1).
3
Q
Complete:
It was once thought that all vitamins contained (________). However, it was later discovered that this was not the case, and ‘vitamine’ was changed to ‘vitamin’.
A
nitrogen (amines)
4
Q
Different chemical forms of each vitamin exist, these are called _____ and are generally similar in structure.
A
vitamers
5
Q
How many vitamins are there?
Name them indicating which of the 2 categories they belong to?
A
There are 13 vitamins
Fat-soluble - vitamins A, D, E, K.
Water Soluble - vitamin C and the B vitamins (thiamine, riboflavin, niacin, pantothenic acid, biotin, B6, B12, and folate).
6
Q
What does fat soluble mean in terms of vitamins?
Where are water-soluble vitamins absorbed?
A
Fat soluble: Absorbed with fat in the small intestine into lymphatic capillaries and then into the blood. These vitamins are readily stored.
Water-soluble vitamins are absorbed in the small intestine directly into the blood. Storage is minimal (exception = B12), and easily excreted, if in excess.
7
Q
What are the key functions of vitamins and where are they absorbed?
A
- Supporting the immune system.
- Regulating gene expression.
- Supporting neurological activity.
- Facilitating ATP production.
- Manufacturing of blood cells.
- Regulation of hormones.
They are mainly absorbed in the small intestine
8
Q
The body cannot produce vitamins with the exception of which one?
A
Vitamin D
9
Q
Which vitamins are essential in the process of energy production?
If there is a deficiency of these vitamins this can result in poor ___ production
A
B1, B2, B3, B5
ATP
10
Q
Give an example of a vitamin which facilitates physiological functions in the body but is not a physical part of the end result
A
Vitamin C facilitates collagen synthesis but is not a physical part of collagen
11
Q
What is a co-factor?
A
An essential component for enzyme activity
12
Q
Vitamins do not occur in isolation in nature. How could this impact our view of supplements?
A
Supplements do not offer the same therapeutic advantages as consuming a spectrum of nutrients via food.
13
Q
Vitamins (as they occur in food) are relatively ‘inert’ until the body activates them. How are they activated?
Give an example of a co-factor needed for the action of the CYP450 enzyme system needed for phase 1 liver detoxification
A
With co-factors
B-vitamins. Therefore, B vitamins can be used as part of a liver support programme
14
Q
Define insufficiency
A
Sub-clinical deficiency (i.e., vague symptoms)
15
Q
Define deficiency
A
deficiency greater than insufficiency in amount of something needed
16
Q
List the five stages of insufficiency to deficiency of vitamins?
A
1.Preliminary reduction of stores.
2.Reduction in enzyme activity.
3.Physiological impairment (early signs and symptoms).
4.Classical deficiency syndromes.
5.Terminal tissue pathology.
17
Q
True vitamin deficiencies are rare with the exception of which two vitamins?
A
Vitamin B12 and vitamin D.
Most cases in clinics are insufficiency states
18
Q
Which was the first vitamin to be discovered?
A
Vitamin A
19
Q
What are the active forms (vitamers) which execute the functions of vitamin A?
Depending upon what the body requires, retinol will be oxidised to the different forms. What are these forms?
A
Retinol, retinal and retinoic acid.
retinol →retinal →retinoic acid
20
Q
What happens if the body doesn’t need vitamin A at the time it is consumed?
A
It will remain as retinol and be stored in the liver.
21
Q
All forms of vitamin A work on different body parts, on which part of the body does the following work:
1) Retinol
2) Retinal
3) Retinoic Acid
A
1) Health of the Retina
2) Vision, visual pigments of rod & cone cells of retina
3) Growth & differentiation of epithelial cells
22
Q
What are the two forms of vitamin A?
A
Pro-vitamin A & Pre-formed vitamin A (Retinol)
23
Q
Where does the Greek word carotene come from?
A
Karoton for ‘carrot’ — orange pigments
24
Q
Where is Pro-vitamin A converted into the active (usable) form of vitamin A (retinol)?
A
In the small intestinal epithelium and liver.
25
How does pro-vitamins differ from pre-formed vitamins?
Pro- A substance that can be converted into a vitamin
Pre- A vitamin that is already formed
26
Where can pro-vitamin A be found? And what are the most active types?
Carotenes (or carotenoids) are examples of pro-vitamin A.
The most active pro-vitamin carotenes are: α-(alpha), β-(beta) and γ-(gamma) carotenes and cryptoxanthin.
27
Are there toxicity concerns with dietary carotenes?
Dietary carotenes are converted to vitamin A only as needed, so there are no toxicity concerns.
28
There is a great deal of variability of the absorption rates of carotenoids, where are they absorbed and at what rate?
How could you increase absorption of carotenoids?
The absorption of carotenoids in the small intestine varies between 5% and 60%.
As carotenoids are fat-soluble. Drizzle with coconut oil or olive oil to optimise absorption.
29
What is the most effective way to liberate carotenoids from food?
A way to increase the bioavailability of carotenoids is to cook (slightly steam) these foods, e.g., carrots. This cooking method is thought to most effectively liberate carotenoids from cells.
30
Where can pre-formed vitamin A be found?
Only in animal foods and can be used as it is.
31
Pro-vitamin A is produced by plants. Name some rich sources of where it can be found?
Algae, fungi and bacteria. Rich food sources: Dark green, yellow / orange vegetables and fruit, e.g., carrots, squash, mango, spinach, sweet potatoes.
32
Pre-formed-vitamin A is found in animal foods. Name some examples of where it can be found?
liver, fish liver oils, egg yolk, mackerel, salmon.
33
Which enzyme converts carotenoids to retinal in the intestinal epithelium and liver is encoded by which gene?
BCO1 gene
34
Which conditions can reduce carotene conversion?
Hyperlipidaemia, liver disorders, diabetes and hypothyroidism
35
What can excessive intake of carotenoids lead to? And what could it be mistaken for?
What could a sallow yellow complexion (i.e., pale or pasty), especially in the face indicate according to TCM?
A non-dangerous yellowing of the skin. However, yellowing of the skin might also be associated with disorders of the liver, gallbladder.
A Spleen Qi deficiency. In TCM, this refers to ‘weakness’ in digestion function.
36
What is the absorption rate of pre-formed vitamin A?
What is the recommended dosage for pre-formed vitamin A?
About 70–90% of dietary retinol is absorbed ―this is a key reason that animal food sources of vitamin A can lead to vitamin A toxicity (liver particularly).
Supplemental range: Adults maximum 3000 mcg (micrograms) preformed A. Higher doses are appropriate in some situations but should only be used short-term.
37
Why is it best to avoid isolated beta-carotene supplementation?
It is recommended to avoid isolated beta-carotene supplementation, as it was shown to worsen the progression of lung cancer patients in a research study (recall that antioxidants do not work in isolation).
38
As carotenes (provitamin A) don’t have the same vitamin A activity as preformed vitamin A a method has been invented in order to show the real retinal potency of a given carotenoid in supplemental form. What is it called?
The amounts of vitamin A are expressed as mcg of retinol activity equivalents (RAE)
39
What is the conversion ratio of beta-carotene in food to retinol?
What is the conversion ratio of beta-carotene in supplements to retinol?
1 RAE = 1 mcg of retinol = 12 mcg of beta-carotene = 24 mcg of alpha-carotene or beta-cryptoxanthin from dietary sources.
Supplements conversion is: 2mcg beta-carotene = 1mcg retinol.
40
What is the meaning of the word rhodopsin?
The visual purple
41
Vitamin A is required for vision and eye health. What are two functions that it is required for?
Required for rhodopsin ― the light-sensitive protein involved in converting light into an electrical signal that goes into the brain’s visual cortex, giving the message of sight.
It is also necessary for corneal health.
42
Name four therapeutic uses of Vitamin A with regard to vision and eye health
*Photosensitivity
*Visual loss
*Night-blindness
*Senile cataracts
43
Vitamin A is required for immunity. What are two functions that it is required for?
*Enhances T-cell proliferation and interleukin-2 secretion.
*Supports first line of immune defence (skin and mucous membrane barrier).
44
Name a therapeutic use of Vitamin A with regard to immunity?
Recurrent infections, e.g., respiratory tract infections.
45
Vitamin A is required for gene expression and cell differentiation. What are three functions that it is required for?
*Control of cell differentiation and turnover. Regulating the expression of over 500 genes, affecting the synthesis of proteins that regulate cell functioning.
*Key as a preventive measure to support healthy gene expression.
*Synthesis of glycoproteins which support normal development of bones, teeth and skin.
46
Name some therapeutic uses of Vitamin A with regard to cell differentiation and gene expression.
*Acne
*Anaemia
*Cervical dysplasia
*Hair loss in women
*Fracture repair
*Lichen planus
*Osteoarthritis
*GIT ulceration
*Vaginitis
*Periodontal disease
47
Vitamin A is required for reproduction. What are three functions that it is required for?
*Reproductive & embryonic health.
*Required for spermatogenesis in men.
*Required for egg (ovum) development and implantation.
48
Vitamin A is required for it's antioxidant properties. What are two functions that it is required for?
*Preformed and provitamin A have antioxidant properties.
*The foods rich in carotenoids are also rich in other antioxidants, again highlighting that they don’t work in isolation.
49
Name some therapeutic uses of Vitamin A with regard to reproduction?
"*Infertility (male and female)
*Fibrocystic breast disease
50
Name some therapeutic uses of Vitamin A with regard to antioxidant properties?
"*Used in various therapies, including carrot juicing for cancer (Gerson therapy).
*Disease prevention
51
Describe how to make carrot/apple juice as used in the Gerson therapy?
*Approx. 3 large carrots: 1 large green apple (8–12 oz each).
*Use only organic produce and a cold-press juicer.
*Use sour apples such as Granny Smith (these are higher in malic acid and pectin which support heavy metal chelation, and also extract more nutrients from the carrots / apple).
*Wash and brush the carrots; cut off the ends. Do not peel.
*Wash the apples, cut them and remove the stem / seeds.
*Consume as soon as possible to stop the juice oxidising.
52
What is hyperkeratosis?
thickening of the stratum corneum (‘goose flesh’)
53
What should you consider doing before supplementing with vitamin A?
Add 1-2 portions of beta-carotene rich foods a day
54
Name six signs and symptoms of vitamin A deficiency?
*Vision impairment at night is an early sign: Loss of sensitivity to green light, unable to adapt to dim light and night blindness. Prolonged deficiency can lead to blindness.
*Hyperkeratosis of skin of upper arms.
*Reduced skin integrity —rough dry skin, acne, eczema, poor wound healing. Dry hair.
*Poor bone growth / development.
*Poor sense of taste and smell.
*Lowered immunity (recurrent infections).
55
Which pathologies reduce carotene conversion?
Diabetes mellitus, thyroid, and liver disease
56
How does alcoholism affect vitamin A?
Accelerates the breakdown of liver-stored retinol; absorption and carotene conversion is reduced. Increased vitamin A toxicity potential; not supplemented with preformed A.
57
How does poor gut health affect vitamin A?
Name a condition which could be implicated.
Name a drug which may affect it.
Poor gut health (lack of absorption in small intestine) and conditions that affect fat absorption, e.g., cystic fibrosis,
statins
58
How would zinc deficiency or protein malnutrition affect vitamin A?
Zinc and protein are required to make Retinol Binding Protein (RBP). RBP moves vitamin A from liver storage to tissues for utilisation. Without zinc, vitamin A is trapped. So optimise intake of zinc-rich foods.
59
What is a hepatocyte?
liver cell
60
How long it take to reach vitamin A toxicity?
How can vitamin A toxicity affect the following:
Embroylogical development?
Bone health?
Liver health?
Skin health?
Long-term and regular intake -roughly 5–10 times the recommended nutrient intake over many months
Can negatively affect gene regulation during embryological development leading to birth defects (e.g., cleft lip).
May increase osteoclast activity and lead to bone fractures.
Can damage hepatocyte cell membranes (causing liver disease).
Can cause dry, red and scaling skin
61
What conditions could vitamin A toxicity cause?
Name a vitamin A drug interaction?
Can lead to hyperlipidaemia, amenorrhea and anorexia.
warfarin, as it decreases vitamin K absorption (increasing bleeding risk).
62
Technically vitamin D is not strictly a vitamin, why is this?
What does the word ergocalciferol mean?
Vitamin D is not strictly a vitamin since it can be synthesised in the skin in response to sunlight.
‘ergo’ = plant sourced D
‘chole’ = animal sourced D
63
Why would you require dietary sources of vitamin D?
Name two dietary sources of vitamin D and list types and example
Dietary sources are only required in the absence of adequate sunlight (UVB)
Plant source: Vitamin D2 (ergocalciferol D2) — found in mushrooms (fungi), but these require good sun exposure.
– Animal source: Vitamin D3 is 7-dehydroxycholesterol (cholecalciferol D3) — found in cod liver oil, oily fish (herring,
mackerel, sardines, wild-caught salmon) and organic egg yolks.
64
What functions do vitamin D2 and D3 have?
In which organs are vitamin D2 and D3 activated?
Vitamin D2 and D3 do not have any direct functions they both first need to be converted (hydroxylated).
Liver and kidney
65
At what range does conventional medicine consider serum ranges (of calcidiol) to be sufficient?
At what range does conventional medicine consider serum ranges (of calcidiol) to be deficient?
At what range does naturopathic medicine consider serum ranges (of calcidiol) to be sufficient or optimal?
over 50 nmol / L
Below 25 nmol / L is almost universally agreed to be deficient.
The optimal range is generally considered to be 75–125 nmol / L (some variance). So are your clients’ levels ‘sufficient’ or ‘optimal’?
66
What is 1,25-Calcitriol?
The active form of vitamin D
67
What is the meaning of the term endogenous?
from within the body
68
If you're outside how long does your shadow need to be in order to get enough sunlight to make vitamin D?
When are serum levels of vitamin D usually the highest and lowest?
The same height or shorter that you
Serum levels are usually highest at the end of the summer and lowest at the end of winter.
69
What can block the conversion of vitamin D?
Sunscreens and window glass block the conversion to vitamin D by blocking UVB radiation.
70
How long can vitamin D be stored in the liver?
vitamin D can be stored in the liver for 4 months.
71
How long does it take to produce 400IU of vitamin D in fairer skin types?
And what is the difference to make the same amount with a darker skin tone?
What does μg stand for?
10 minutes of summer sun exposure results in endogenous production of about 400IU in fairer skin types. In darker skin tones it can take 3–6 times longer to produce the same amount of D3.
Microgram
72
**Regarding vitamin D.**
What should our focus be when coming across a deficiency to avoid a symptom based approach?
What supplemental dose can be used without adverse effects?
How often should vitamin D levels be tested?
What dosage of vitamin D would be recommended in the case of a pronounced deficiency: (<10 ng / mL)?
first address the cause of the deficiency
A supplemental dose of 4000 IU / day has been used without adverse effects. 1 μg of cholecalciferol = 40 IU.
It is advisable to test vitamin D levels every four months to adjust dosing where appropriate.
50,000 IU of vitamin D3 orally once weekly for 2–3 months, or 3 times weekly for 1 month.
73
Regarding supplementation: why is D3 preferred above ergocalciferol?
Ergocalciferol is less than one-third as potent as cholecalciferol, so D3 is favoured for supplementation. D3 supplements also stay in circulation longer.
74
What is a key function of vitamin D in the body?
A key function of vitamin D is to maintain serum calcium and phosphorus homeostasis.
75
What is the nuclear transcription factor known as?
The actions of vitamin D are mediated through a nuclear transcription factor known as the vitamin D receptor (VDR) within the nucleus of each cell. VDR activation is thought to directly and / or indirectly regulate 100 to 1,250 genes.
76
How does vitamin D support bone health & which co-factor is needed?
increases intestinal calcium absorption. K2
77
How does vitamin D support immune function & regulation?
--Enhancing innate immune system
–Regulation of T-helper cells
–Producing antibacterial peptides.
–Inhibiting eosinophils
–Reducing inflammatory cytokines (e.g., IL-6 and TNF-α) and prostaglandin production.
78
How does vitamin D support GIT health?
* The vitamin D receptor (VDR) helps to regulates mucosal inflammation.
* Vitamin D has a role in commensal bacterial colonisation.
* Intestinal VDR stabilises tight junctions.
79
How does vitamin D support anti-cancer activity?
* Enhances the anti-tumour activity of innate immune cells.
* Regulates multiple genes through the VDR, and inhibits angiogenesis.
80
How does vitamin D support insulin?
* Activates transcription of the insulin gene (increasing insulin secretion).
* Increases cellular sensitivity to insulin.
81
Detail how the balance of vitamin A and D is essential for proper gene transcription.
*The retinoid X receptor (RXR) is a type of nuclear receptor that is activated by vitamin A.
*Together the VDR / RXR forma complex with DNA for transcription.
*So, from a disease-prevention approach, maintaining healthy levels of vitamins A and D is crucial for correct gene expression.
82
List three signs/symptoms of vitamin D deficiency?
* Rickets and osteomalacia: Demineralised bones. Rickets occurs in children, whilst osteomalacia affects adults. Presents with bone pain and bowing of lower limb bones.
* Osteoporosis (brittle bones) —fractures.
* Severe asthma in children.
* Poor immunity or immune dysfunction (autoimmunity, allergies), insomnia, nervousness, depression.
* Menstrual irregularities (increases FSH / LH production).
* Non-specific Musculoskeletal pain and fatigue
83
What are some of the causes of vitamin D deficiency?
*Inadequate UVB sun exposure and overuse of conventional sunscreens.
*Dietary factors such as excessive animal protein or calcium intake can lead to lower blood levels of vitamin D by affecting its rate of formation and clearance.
*Lack of dietary fats (it is a fat-soluble vitamin), and a lack of magnesium (it is a co-factor for vitamin D synthesis).
*Breastfeeding without adequate sunlight/supplementation.
*Impaired liver functionality (compromised vitamin D conversion) due to excess alcohol, drug and caffeine use, as well as a large toxic burden from the diet (e.g., pesticides), environmental and household chemicals. Therefore, it is crucial to support liver functionality by removing the toxic burden.
*Elderly patients and those with a history of kidney disease.
*Poor intestinal absorption of dietary vitamin D (e.g., due to cystic fibrosis, coeliac disease, dysbiosis) and a lack of bile. Therefore, it is crucial to support digestive health (i.e., good digestive secretions, a healthy microflora).
84
Vitamin D synthesis from sunlight does not cause toxicity, what does and what are the symptoms?
*Main toxicity symptoms due to vitamin D-related hypercalcaemia: nausea, diarrhoea, vomiting, weakness, hypertension, constipation.
*Toxicity can occur taking supplemental vitamin D at more than 50,000 IU per day for one to several months.
*Individuals with vitamin D toxicity usually have blood levels above 375 nmol / L.
*EFSA Tolerable Upper Intake Level for Adults: 4000 IU / day.
85
Name a drug interaction associated with low vitamin D?
Osteomalacia risk due to low vitamin D is increased with use of barbiturates and anticonvulsants
86
Vitamin E is a generic term for two families of fat-soluble compounds with vitamin E activity, what are they called?
Tocopherols and tocotrienols. Both families contain at least four forms: Alpha, beta, gamma and delta. All forms exist within natural foods.
87
Which form of vitamin E is the only form recognised for human nutrition?
α-tocopherol
88
What process destroys up to 80% of vitamin E?
What are the best sources of vitamin E?
Freezing
Fresh, raw food sources are best: Sunflower seeds, almonds, pine nuts, olive oil, avocado, sweet potato, spinach.
89
What is the meaning of the word tocopherols / tocotrienols?
From Greek for ‘to bear a pregnancy’, after being first identified as a dietary fertility factor in rats
90
Where is vitamin E stored in the body?
Stored to the greatest extent in adipose tissue.
91
Naturally sourced vitamin E can be seen on labelling as d-alpha-tocopherol. Which added letter would denote synthetic forms of vitamin E?
dl-alpha-tocopherol. L isomers are less active. Synthetic forms of vitamin E are derived from petroleum oil and should be avoided.
92
How does vitamin E act as an antioxidant in the body?
* Protects the following from oxidation:
– Polyunsaturated fatty acids (PUFA) cell membranes
– Nerve sheaths
– Cholesterol (↓ LDL oxidation)
* A vital ‘chain-breaking antioxidant’.
* Vitamin C and selenium support the activity of vitamin E by rejuvenating oxidised vitamin E. So, ensure an adequate intake of all antioxidants to optimise the effects of vitamin E.
93
How does vitamin E help with immunity in the body?
* Increases phagocytic activity
* Differentiation of immature T cells in the thymus
* Antioxidant and mild anti-inflammatory properties
94
How does vitamin E act as an anti-coagulant in the body?
Inhibits platelet aggregation and vitamin K activity (↓clotting factors)
95
How does vitamin E assist the endocrine system?
* Improves insulin action (possibly improves insulin resistance)
* Modulates oestrogen receptors and activity
96
How does vitamin E contribute to skin repair?
Traditional topical use, although mechanism not understood.
97
How does vitamin E deficiency typically present?
* Red blood cell destruction (due to erythrocyte oxidation (haemolytic anaemia)
* exhaustion after light exercise.
* Easy bruising and slow healing (fewer antioxidants).
* Nerve damage (e.g., neuropathy) due to oxidation.
98
How did vitamin K get it's name?
Named after K for koagulation (German spelling); discovered during investigation of bleeding disorders in animals.
99
Name a good dietary source of vitamin K1 (phylloquinone)?
Vitamin K1 is found in green leafy vegetables — natural form, making up about 80–90% of daily intake. K1 must be converted to K2 in the body to be utilised.
100
How is vitamin K2 produced in the body?
Synthesised by bacteria, found in fermented foods, making up around 10%. Probiotics can support intestinal K2 production. K2 synthesis by bacteria occurs in the human jejunum and ileum and is absorbed to a limited extent.
101
How is vitamin K3 usually used?
K3 (menadione) is a potentially toxic, synthetic form used in livestock.
102
What are the richest food sources of vitamin K?
Natto and dark green leafy vegetables. Best absorbed with some dietary fat, e.g., steamed broccoli and kale with extra virgin olive oil.
103
What is the optimal dosage of vitamin K considered to be?
Optimal intake is 300–500 mcg / day. Few countries set a daily req. K2 is better absorbed and tends to stay within the body for longer.
104
How does vitamin K contribute to blood clotting?
Vitamin K is required for the formation of 4 out of the 13 clotting factors (II, VII, IX, X)
105
How does vitamin K contribute to bone mineralisation?
* Osteocalcin (a calcium binding protein in bones) requires vitamin K for synthesis.
* Osteocalcin synthesis by osteoblasts is regulated by active vitamin D (calcitriol).
106
Name some causes of deficiency of vitamin K
* Liver diseases, warfarin, antibiotic use, fat malabsorption issues.
* Maternal considerations: Vitamin K transfer to the foetus via the placenta is not significant (although it is generally adequate). Maternal medications such as antibiotics, anticonvulsants and warfarin can dramatically reduce stores.
* A vitamin K injection is offered at birth to newborns to prevent potential haemorrhagic disease.
107
What is a sign of vitamin K deficiency?
Excessive bleeding (haemorrhages), bruising, bone fractures, soft tissue calcification.
108
What are some considerations of the vitamin K injection for newborns?
* Undesirable preservatives (e.g., polysorbate 80; aluminium in the US).
* Has not been tested for adverse effects such as mutagenicity.
* It is a synthetic chemical (despite the name ‘vitamin’).
* The risk in full-term babies is 1:100,000.
* A larger dose is given than a newborn requires.
109
What are the alternatives to vitamin K injections for newborns?
* Delayed cord clamping until the placenta has fully pulsed out.
* Increase intake of vitamin K-rich foods (e.g., leafy greens) before due date, and support mother’s microflora (K2).
* Nettle leaf infusions are a great source of vitamin K2, too.
* Vitamin K amounts in the newborn’s blood increase daily.
110
What is the active form of vitamin B1 (Thiamine) in the body? Which co-factor is essential and what is conversion impaired by?
‘thiamine pyrophosphate’ (TPP)
conversion to this enzyme is dependent on magnesium, and impaired by alcohol.
111
How long does the body store vitamin B1?
Bodily stores of B1 would last for approximately 1 month.
112
Name some food sources of vitamin B1?
*Yeast extract, peas, oranges, nuts (e.g., macadamia), pulses, sunflower seeds, whole grains, meat / fish.
113
How does vitamin B1 help with:
energy production in the body?
the nervous system function in the body?
Energy:
*Crucial for carbohydrate, as well as fat and protein metabolism.
*Needed for the formation of Acetyl-CoA (key for ATP production).
Nervous:
"*Acetyl-CoA is an important precursor of acetylcholine.
*The amino acids that are metabolised by thiamine can be used to create neurotransmitter. E.g., GABA.
114
The more _______ you eat the more B1 you need
carbohydrate
115
Absorbtion of B1 is impaired by?
Alcohol, tea (tannins), coffee, the OCP, stress and antacids.
116
What is the primary deficiency disease of B1?
What is the name of the deficiency disease of B1 when found in alcoholics?
Beriberi is the primary deficiency disease. Most forms are rare in the West. A white rice diet is thiamine depleted (these are at risk).
Alcoholics are particularly prone to deficiency —‘cerebral beriberi’ (Wernicke-Korsakoff syndrome) is most common Western cause.
117
What are the symptoms of subclinical deficiency of B1?
*Depression, irritability, fatigue, memory loss, muscle weakness and cramps, GIT disturbance.
*Be aware that elderly people are frequently more depleted of thiamine and can benefit from it.
118
When might you see toxicity with regard to B1?
Only seen in supplementation (i.e., 5g daily), but is rare.
119
What is the name of B2?
What are the uses of B2 in the body?
Name some food sources of vitamin B2?
Riboflavin
Vitamin B2(riboflavin) is vital for energy production and the metabolism of carbohydrates, fats and protein.
Yeast extract, spinach, wild salmon, mushrooms, almonds, quinoa, lentils, kidney beans, organic eggs, meat.
120
What effect would you see in the body when supplementing with B2?
B2 is a fluorescent green / yellow compound —supplements over 27 mg (maximum absorbed amount) will colour urine bright yellow.
121
Give 3 key uses of vitamin B2 production in the body?
Energy:
*Metabolism of carbohydrates, fats and proteins.
*For Krebs cycle and beta-oxidation
*B2 is a constituent of 2 key energy carriers: FAD (flavin adenine dinucleotide) and FMN (flavin mononucleotide)
Liver detox:
"*Detoxification via CYP450 enzymes (phase I liver detoxification system).
*Regeneration of glutathione
Iron Metabolism:
*B2 is required for iron metabolism
122
What is the maximum absorption of B2?
Bioavailability of B2 is impaired by...?
What is the dosage of B2?
27mg
*Impaired by, Copper, zinc, caffeine, theophylline (in chocolate), saccharin
*Smoking can reduce levels in the body. B2 demands are increased with heavy exercise, pregnancy, and ageing. Do not exceed daily recommendations in pregnancy and lactation.
*Doses between 90–400 mg per day (split through the day).
123
Name some signs and symptoms of poor intake of B2?
*Sores at the margins of the lips/mouth corners.
*Red, dry, atrophic tongue.
*Scaly dermatitis (especially around the mouth, nose, eyes and ears) and red, tired and gritty eyes.
*Fatigue, weakness, poor concentration, depression.
*Deficiency (although rare) can also cause alopecia.
124
Vitamin B3 is not strictly a vitamin as it can be synthesised by the body, what is needed to make it? and what is the name of vitamin B3?
Vitamin B3 (niacin) is not strictly a vitamin as it can be synthesised by the body from the amino acid tryptophan: 60 mg of tryptophan produces 1 mg niacin.
125
Name some food sources of B3?
Mushrooms, green leafy vegetables, yeast extracts, sunflower seeds, salmon, sardines, peanuts, avocado, meat and poultry. Cooking reduces B3 in foods. Tryptophan-rich foods, e.g., bananas, turkey.
126
What is the recommended dosage of B3?
What co-factors are needed for synthesis of B3 from tryptophan?
RDA- 16-18 microgram
Recommendations are stated as niacin equivalents (NE). Equal to the total niacin compounds in food plus 1/60thof the tryptophan content of the food (i.e., 60 mg tryptophan → body produces 1 mg B3).
Synthesis of B3 from tryptophan requires B2, B6 and iron (cofactors).
127
What is a niacin flush? How can it be avoided?
Niacin flush: Skin flush and itch due to supplementation.
Avoid flush by using initial dose of 25 mg (gradually increased) alongside 1 g vitamin C.
128
Where is niacin absorbed & stored?
*Absorption of vitamin B3 is in the small intestine.
*Stored niacin (NAD) is mostly in the liver, heart, muscles and kidney.
129
How does vitamin B3 help with:
Energy production in the body?
Cardiovascular system?
Insulin?
Energy:
*The two coenzymes (NAD, NADP) participate in:
–Glycolysis
–Acetyl CoA formation
–Krebs Cycle
–Fatty acid oxidation
Cardiovascular:
"*Lowers secretion of LDL
*Vasodilatory effects (lowers BP)
Insulin:
*Glucose-tolerance factor (GTF), which plays an important role in the insulin response, employs niacin.
130
What are the four Ds associated with severe B3 deficiency?
*Severe deficiency (‘pellagra’): Four Ds —diarrhoea, dermatitis (characteristic collar rash), dementia, death (within 4–5 years).
Note: Pellagra can occur in diets deficient in both protein and niacin. It is common in Africa, Indonesia and China. In the West, pellagra is associated with homelessness, alcoholism, or anorexia nervosa. Crohn’s or intestinal disease may also lead to deficiency. Pellagra is treated with up to 500 mg B3 daily by a doctor.
131
What are the symptoms of mild deficiency of B3?
Mild deficiency / insufficiency symptoms: Unrelenting fatigue, vomiting, depression, indigestion, canker sores, sensitivity to strong light, red tongue, and inflamed gums
132
Adverse events can occur with B3 toxicity, name some. And name a pathology which is made worse with Niacin supplementation
*Adverse events can occur at high levels: Hypotension, hyperuricaemia, flush, hypothyroidism, hepatotoxicity.
*Do not megadose.
*Niacin competes with urate for excretion so supplementation can worsen gout (200 mg+ / day).
133
What is the name of vitamin B5?
Name some food sources of B5?
Pantothenic Acid
Richest food sources include shiitake mushrooms, avocados, nuts, seeds, fish and meat. However, it is found widely distributed in almost all foods
134
Vitamin B5 is required to make ________
What is the meaning of the word Pantothenic?
coenzyme A (CoA)
from Greek for ‘found everywhere’ (i.e., found in many foods)
135
How is B5 useful in:
ATP production?
Fat metabolism?
ATP:
*Metabolism of carbohydrates and proteins.
*Required for Acetyl CoA formation (review Biochem2)"
Fat:
*The synthesis and degradation of fatty acids.
136
How does B5 affect stress hormones?
*Acetyl-CoA → neurotransmitters (i.e., increased GABA)
*A co-factor for stress hormones (used up quickly when stressed)
137
What are the symptoms of B5 deficiency?
*Deficiency is rare. However, depletion may occur with high alcohol use, prolonged stress and recent surgery.
*Deficiency symptoms: Burning sensation in feet and tender heels, fatigue and abdominal distress.
138
What is the chemical name of vitamin B6?
What are the food sources of B6?
Pyridoxine
Whole grains, green vegetables, sunflower seeds, pistachios, walnuts, bananas, lentils, avocados, meat, fish.
139
How does B6 affect:
Neurotransmitter production?
Red blood cell formation?
Methylation?
Energy production?
Neurotransmitter:
*Synthesis of
–GABA
–Dopamine
–Noradrenaline
–Serotonin
Red blood cell:
Used for haem production
Methylation: Lowers homocysteine
Energy production:
Amino acid metabolism releases stored glucose
140
There are certain circumstances in the body where our need for B6 goes up, name some?
Alcohol dependence, long periods of high stress, pregnancy —particularly in the third trimester, hormonal imbalances, hyperhomocysteinemia (with folate / folic acid and vitamin B12).
141
What are the symptoms of low B6?
*Deficiency is rare and occurs alongside other deficiencies.
*Symptoms: Low B6 affects the metabolism of fatty acids leading to skin lesions and dermatitis. Tongue inflammation, recurrent mouth ulcers and sores on the corners of the mouth, hormonal imbalance (e.g., PMS), anaemia (fatigue, pallor, etc.), and depression.
142
Several drugs deplete B6 levels & levels should be increased. What are they?
This includes anticonvulsants, antibiotics, alcohol, chemotherapy drug ‘docetaxel’ and the oral contraceptive pill (OCP). *Levodopa (Parkinson’s medication): The combination of carbidopa and levodopa do not have the B6 depletion problem. However, levodopa (on its own) is broken down by B6 so it should not be supplemented (beyond 5–10 mg / day).
143
What are the toxicity levels of B6?
100–200 mg / day supplements long-term can lead to toxicity symptoms including neuropathy, acne, headache, nausea.
144
Vitamin B7 is known by several names, what are they?
What are the food sources of biotin?
Vitamin B7/ B8/ H/ Biotin
Egg yolk, yeast, whole grains, cauliflower, sweet potato, nuts, meat, oily fish.
145
_____ egg whites contain a protein called avidin which joins with biotin making it unabsorbable.
Avidin is denatured by _____
Raw
Cooking
146
How does biotin help with:
Gene regulation in the body?
Blood sugar regulation?
Gene Regulation:
*Regulates gene expressions (e.g., modifies the activity of transcription factors) which are crucial for metabolism.
*Particularly supportive of rapidly regenerating tissues, e.g., skin, hair and nails.
Blood Sugar:
In combination with the mineral chromium, biotin has been shown to improve blood-glucose control (reducing HbA1c); i.e., 2 mg of biotin with 600 mcg of chromium
147
What are the symptoms of biotin deficiency?
Which type of diet may enhance biotin synthesis & absorption?
What might inhibit biotin absorption?
Dermatitis, dry scaly flaky skin (i.e., mouth and nose), smooth pale tongue, hair thinning and loss, depigmentation.
vegetarian
Anticonvulsant drugs and alcohol may inhibit absorption.
148
Biotin.........
interferes with laboratory tests
supplementation
149
What is vitamin B9 also know as?
What is the synthetic version of B9 called?
Folate
Folic acid is a synthetic supplement or fortification form and is not found in nature. Folinic acid and levomefolic acid are also synthetic forms of this vitamin.
150
What are some food sources of vitamin B9?
Where is B9 stored?
Which enzymes are required for the absorption of B9?
Leafy greens, asparagus, avocado, Brussels sprouts legumes, citrus fruit (especially oranges) and liver.
Main storage site is the liver (50%).
Pancreatic enzymes
151
After B9 absorption what is added to folate to make it deliverable to body cells?
What removes the methyl group from folate?
How much more available is folic acid considered to be over dietary folate
A methyl group (-CH3)
B12
1.7x more
152
What is the adverse effect of high folic acid supplementation?
If supplementation of folate is indicated which form is best?
Nausea
Methylated form
153
How does folate help with:
Cardiovascular health?
Formation of red blood cells?
Embryo health?
Cardio:
Methylation of homocysteine to methionine.
RBC:
Required for erythrocyte synthesis. Without this, they are large and immature.
Embryo:
Required for the healthy development of the neural tube.
154
What are the signs & symptoms of folate deficiency?
What factors may be related to folate deficiency?
Affecting rapidly dividing cell types; skin, GIT and blood cells: Skin and digestive issues, megaloblastic anaemia (severe deficiency).
Alcoholism, OCP, diuretic and aspirin use. GIT disorders, diets low in green leafy vegetables and old age. Those on methotrexate and anticonvulsants should consult their GP regarding vitamin B9 use.
155
What is the dosage of folate for conception?
Preconception and conception care: 600 mcg / day beginning prior to conception helps avoid neural tube defects.
156
Naturally occurring folate is considered safe to use. However, folic acid supplements may mask the _______ ________ of vitamin B12 deficiency and may hasten the development of irreversible nerve damage.
megaloblastic anaemia
157
People with an MTHFR polymorphism may be more susceptible to issues arising from ____________ with folic acid (or that in fortified foods). _____ forms of the vitamin ONLY should be recommended to clients.
supplementation, active
158
Folic acid supplements have ___ ____ drug interactions of all vitamins
the most
159
What is the chemical name of vitamin B12?
What does the word cobalamin mean?
Cobalamin
from cobalt + vitamin
160
Vitamin B12 is synthesised by ______
Where is B12 stored in the body and for how long?
bacteria
In the liver for between 3-5 years
161
What are some vegan B12 food sources?
Vegan:
Chlorella pyrenoidosa (e.g., 9 g per day)
A substantial amount (133.8 μg/ 100 g) of vitamin B12 has also been found in dried Korean purple laver (Porphyrasp.).
Nutritional yeast, sea vegetables (nori, kombu, kelp and dulse), shiitake and Lion’s mane mushrooms.*
Animal:
What are some animal B12 food sources? Meat, liver, milk, cottage and feta cheese, organic eggs, fish (esp. sardines, mackerel and wild salmon).
162
How does B12 help with:
The nervous system?
Erythropoiesis?
Methylation?
Energy production?
The nervous system:
*Myelin production.
*Neurotransmitter production (dopamine, serotonin).
*Choline—key for brain function"
Erythropoiesis:
*B12 is required for erythropoiesis.
Methylation:
*Homocysteine cycle (conversion of the amino acid homocysteine to methionine).
Energy:
*Energy production from fats and proteins.
163
What are the two causes of B12 deficiency?
*Poor nutrition (malnutrition):
–Lack of dietary B12 intake, and a diet rich in highly-processed, nutrient-depleted foods.
*GIT causes (malabsorption):
–Stomach problems (e.g., lack of intrinsic factor, low hydrochloric acid production)
–Low pancreatic enzymes, small intestine issues (e.g., Crohn’s disease, coeliac), high alcohol.
164
The most common cause of deficiency of B12 is malabsorption due to inadequate intrinsic factor production. This is called _____ _______
Pernicious Anaemia
165
Pernicious anaemia is associate with an__________ attack on parietal cells in the stomach.
autoimmune
166
In what states are increased B12 requirements associated?
pregnancy, thyrotoxicosis ( clinical syndrome of excess circulating thyroid hormones, irrespective of the source), malignancy, liver and kidney disease.
167
What are testing reference ranges for serum B12?
What is a more accurate testing method for B12 than serum testing?
*Serum B12 testing reference ranges are typically anything between from 110 ng / L up to 900 ng / L. This is the most common means of assessing B12 conventionally.
* However, many people experience signs of B12 deficiency with normal B12 serum.
A more accurate reflection of B12 levels would involve testing methylmalonic acid (available in serum or urine testing) — gives an indication of how B12 is used in cell metabolism and is the gold standard test.
168
What are the drug interactions for B12?
"The OCP, metformin, excessive alcohol, proton pump inhibitors and H2-receptor antagonists lower B12 levels.
* Calcium may enhance B12 absorption, including with metformin use.
* People with autoimmune disease are considered more at risk of pernicious anaemia.
169
What is the chemical name for vitamin C?
Vitamin C functions as a key ________
Vitamin C does or does not need to be modified by the body to function?
Ascorbic acid
Antioxidant
does not
170
What are some food sources of vitamin C?
What can prevent oxidation of other foods?
All fresh raw fruit and vegetables, particularly peppers, kiwi fruit, papaya, currants, berries, citrus, crucifers, mangoes and tomatoes.
Ascorbate oxidase from lemon or lime juice
171
Where is vitamin C absorbed?
How is vitamin C transported in the body?
In the mouth and the small intestine
via glucose transporters, so high blood glucose levels can inhibit vitamin C uptake significantly.
172
Vitamin isn't stored in the body like other vitamins but where does it concentrate?
What factors increase breakdown or excretion of vitamin C?
There is no specific storage site but it concentrates in the adrenal glands, WBCs, thymus and pituitary
Stress — psychological, chemical, emotional or physiological, fever and viral illnesses. Alcohol, smoking, heavy metals, aspirin, OCP.
173
What action does vitamin C have as an antioxidant?
*Primary water-soluble antioxidant in blood and tissues —protecting proteins, lipids, carbohydrates, RNA and DNA from damage from free radicals.
*Recycles other antioxidants such as vitamin E and glutathione —making them usable again as antioxidants.
*Up-regulates interferons, natural killer cells and T-cells.
174
What action does vitamin C have in:
lowering cholesterol?
Iron absorption?
Endocrine function?
Cholesterol:
Conversion of cholesterol to bile acids (lowering blood LDL levels).
Iron:
*Enhances iron absorption by protecting iron from oxidation. It keeps it in Fe2+ form, not allowing it to become Fe3+, which is not a bioavailable form.
*A dose of 25 mg of vitamin C taken together with a meal increases iron absorption by 65%. Optimum iron absorption may require more than 100 mg / day.
Endocrine:
Synthesis of thyroxine and adrenal steroid hormones.
175
What action does vitamin C have in:
Collagen synthesis?
Neurotransmitter synthesis?
Energy production?
Collagen:
*Vitamin C is a co-factor required for collagen synthesis.
*Important for forming strong tendons, ligaments, and bones, repairing wounds, and improving gum health.
Neurotransmitter synthesis:
A co-factor for the production of serotonin.
Energy:
Transport of long-chain fatty acids into the mitochondria for ATP production
176
What are the two most notable signs of vitamin C deficiency?
–The gums bleed easily around the teeth.
–Capillaries under the skin break spontaneously producing pinpoint haemorrhages.
177
When intake falls to about 1/5 of its optimal store size how long does it take for signs of scurvy to occur?
What are the signs of scurvy?
1 month
–Further haemorrhaging from inadequate collagen synthesis.
–Muscle degeneration and rough, brown scaly skin.
–Wounds do not heal. Bone rebuilding falters; fractures develop.
178
What are some of the reasons for deficiency of vitamin C?
* During stress, the adrenals release vitamin C with other hormones into the blood. The exact role of vitamin C in stress is unknown, but it is known that stress raises vitamin C needs — likely due to additional free radical damage.
* Burns, infections, toxic metal intakes, chronic use of medications and cigarette smoking are among the stresses that increase vitamin C demand.
* Smokers have lower levels of serum vitamin C — 25 mg of vitamin C is lost with every cigarette smoked.
Subclinical deficiency is common: Susceptibility to infections, poor wound healing, fatigue, skin and gum degeneration, petechiae.
179
What is the recommended dosage for vitamin C?
500 mg / day+ vitamin C is a sound general dose.
180
What might a cancer-protective dose of vitamin C be?
A high dietary intake of vitamin C is cancer-protective, and can be mega-dosed (e.g. 25‒75 g intravenously) for cancer support.
181
Why does unabsorbed vitamin C cause GI discomfort and diarrhoea?
Unabsorbed ascorbate from very high doses (3 g / day plus) is a substrate for intestinal bacterial metabolism causing gastrointestinal discomfort and diarrhoea (bowel tolerance).
182
When is high-dose vitamin C contraindicated?
In the third trimester of pregnancy. The baby becomes accustomed to high doses that are unsustainable when born.
183
What are the drug interactions for vitamin C?
May reduce effectiveness of warfarin, statins, some cancer drugs. Increases oestrogen therapy effects. Skews diabetes test results.
184
It is suggested that people with which pathologies avoid vitamin C?
*People with kidney disease and those with a tendency toward gout are prone to forming kidney stones if they take large doses of ascorbic acid beyond a few months
*Be mindful of high-dose vitamin C with haemochromatosis.
185
Pro-vitamin A is produced by plants. Name some rich sources of where it can be found?
Algae, fungi and bacteria. Rich food sources: Dark green, yellow / orange vegetables and fruit, e.g., carrots, squash, mango, spinach, sweet potatoes.
186
List four food sources high in pre-formed vitamin A (Retinol).
Liver, fish liver oils, egg yolk, mackerel, salmon.
