Revision Flashcards
Name the 9 water-soluble vitamins
B1 (thiamin)
B2 (riboflavin)
B3 (niacin)
B5 (pantothenic acid)
B6 (pyridoxine)
B7 (biotin)
B9 (folate)
B12 (cyanocobalamin)
Vitamin C
Name the fat-soluble vitamins and their broad primary function. Which ones are involved in bone health and mineralisation?
Vitamin A* - eye health
Vitamin D* - bone health
Vitamin E - antioxidant
Vitamin K* - blood clotting
*play an important part in bone growth/remodelling
Name the 9 essential amino acids. Which are branch-chain amino acids and what two primary functions do BCAAs have?
Histidine
Isoleucine*
Leucine*
Threonine
Lysine
Methionine
Phenyalaline
Tryptophan
Valine*
*BCAAs - energy and protein synthesis
What is transamination?
To form new non-essential AAs (B6 is needed)
What is s-adenosyl-methionine (SAMe)?
Major carrier of methyl groups
Extra:
- can make adrenaline and melatonin
- folate and B12 are important in the methyl cycle (if low, homocysteine can be high)
Tryptophan is a precursor to which 2 neurotransmitters?
Tryptophan > serotonin > melatonin
Phenylalanine is a precursor for which hormones?
Tyrosine (which in turn make T4), dopamine, norepinephrine and epinephrine
T4 requires several cofactors - what are they?
- Iodine
- Fe
- Se
- Zn
- Vitamin C
What is phenylketonuria (PKU)?
A deficiency which causes phenylalanine (PHE) to build up
Glutamine is the most abundant amino acid in the body. Which cells does it provide primary fuel for?
- Enterocytes (GI cells)
- Lymphocytes (white blood cells)
Glutamine can cross the blood-brain barrier. What does it then become and what is this a precursor for?
Glutamate - an excitatory neurotransmitter - which is then metabolised into GABA - an inhibitory neurotransmitter
Name some key functions of glutamine?
- Protection/repair of GI tract
- immunomodulation
- precursor for synthesis of DNA and RNA
What is glutathione (GSH)?
An antioxidant made from glycine, cysteine and glutamate
Foods high in vitamin C?
Capsicum, broccoli
Broad functions of vitamin C?
- antioxidant
- enzyme cosubstrate
- collagen synthesis
- Fe absorption
Signs of vitamin c deficiency?
- Frequent infections
- rough skin
- blotchy bruises
- poor wound healing
(deficiency disease = scurvy)
B1 functions, signs of deficiency and food sources
Function: energy metabolism
Signs of deficiency: loss of appetite; nausea; apathy; fatigue
Food sources: wholegrains, pork
B2 functions, signs of deficiency and food sources
Function: energy metabolism; part of FAD and FMN
Signs of deficiency: inflammation of mouth, skin and eyelids
Food sources: wholegrains, liver, milk products
B3 functions, signs of deficiency and food sources
Function: energy metabolism; NAD and NADH
Signs of deficiency: pellagra (diarrhoea, dermatitis, dementia)
Food sources: protein-rich foods
B5 functions, signs of deficiency and food sources
Function: energy metabolism; coenzyme A
Signs of deficiency: digestive problems, muscle impairment
Food sources: widespread (liver particularly high)
B7 functions, signs of deficiency and food sources
Function: energy metabolism
Signs of deficiency: skin rash, hair loss
Food sources: widespread
B9 (folate) functions, signs of deficiency and food sources
Function: activates B12, cell division/DNA health
Signs of deficiency: inflamed/swollen tongue (glossitis), cracks/sores in corner of the mouth, shortness of breath, patchy hyperpigmentation of the hands/feet, elevated homocysteine
Food sources: fortified bread and cereals, liver, vegetables, legumes
How is B12 absorbed?
HCL breaks B12 away from amino acids in the stomach; intrinsic factor is released. B12 binds with intrinsic factor in small intestines before this molecule binds with receptors.
B12 functions, signs of deficiency and food sources
Function: activates folate, nerve and red blood cells, DNA
Signs of deficiency: anaemia, sore tongue, fatigue, loss of appetite, mouth ulcers, constipation, nerve damage, paralysis
Food sources: animal products (esp. liver)
What are lutein and zeaxanthin?
Carotenoids (pigments) that don’t get converted to vitamin A but exhibit similar properties and are especially important for eye health
Some signs/symptoms of vitamin A deficiency
Night blindness, dryness of conjunctiva and cornea, bitot’s spots, softening of cornea, dry and scaly skin, bone overgrowth
Vitamin A is somewhat unstable and easily oxidised during processing, storing and cooking. What’s the exception?
Carotenoids (esp. beta-carotene and lycopene) which increase bioavailability
Main functions of vitamin A
- antioxidant
- anti-inflammatory
- immune function
- regulate gene activity
Name some factors that increase demand for fat-soluble vitamins
- low-fat diets (dietary fat is needed for the absorption of vitamin e
- digestive disorders that interfere with normal digestion, e.g. cystic fibrosis, Crohn’s disease
Why is vitamin D not usually considered an essential nutrient?
Because the body can produce it from sunlight and cholesterol in the skin
Good food sources of Vit D?
Mushrrom, barramundi, salmon
Overview of Vitamin D synthesis
- exposure to sunlight converts 7-dehydrocholesterol to pre-vitamin D
- Pre-vitamin D converted to cholecalciferol in the skin over 2-3 days
- Cholecalciferol travels to the liver where hydroxylated before being hydroxylated again in the kidneys into the active form: calcitriol
- Parathyroid hormone stimulates hydroxylation in the kidneys
Major function of Vitamin D
Mineralisation of bones (raises blood calcium and phosphorous levels to maintain homeostasis)
How is calcium homeostasis regulated?
PTH and vitamin D stimulate osteoclast activity to break down bone and release calcium into the blood. Vit D enhances calcium absorption in the intestines.
Calcitonin inhibits osteoclast activity and limits absorption in intestines also inhibits the activation of vitamin D.
Signs of vitamin D deficiency
Fatigue and generalised weakness, muscle/bone pain, lowered immunity, frequent infections, impaired wound healing
The two principal natural forms of Vitamin K are: K1 - phylloquinone and K2 - menaquinones. Which ones if from plants and which one is from animals/bacteria?
K1 - plants and supplements
K2 - animal and bacterial*
Bacterial synthesis in the colon provides up to 80% of Vitamin K requirements
Food sources high in Vitamin K
Cooked spinach, kale, broccoli
Name the 6 macrominerals (needed in large quantities by the body)
Magnesium
Potassium
Calcium
Phosphate
Sodium
Chloride
(Macrominerals Prove Considerably Paramount (in a) Salty Constitution
Which macrominerals are important to fluid and electrolyte balance?
Sodium, chloride and potassium
What are the most clinically relevant microminerals (7 main; two needed in tiny amounts)
Iron
Copper
Iodine
Selenium
Manganese
Chromium
Zinc
[I Care Immensely So Must Control Zealously]
Molybdenum and fluoride
What is iron stored as?
Ferritin
After iron is ingested, how is it freed and absorbed?
Freed from food by gastric HCL; absorbed in the small intestine via iron transporter (ferroprotein) before transferrin carries iron in the blood
Role of hepcidin
Control amount of iron that is absorbed from the diet
What is iron overload called?
Haemochromatosis
(fatigue, darkening of the skin, diabetes, erectile dysfunction, weight loss, joint pain)
Some signs and symptoms of low iron levels
Skin pallor, fatigue, breathlessness, cold hands/feet, poor concentration, glossitis, pale/brittle nails
Microcytic anaemia - when red blood cells are smaller than usual because they don’t have enough haemoglobin
Accumulation of what heavy metal can interfere with iron/calcium?
Lead
What therapeutic diet is high in calcium?
DASH diet
Which macrominerals are important to structural function?
Calcium, magnesium and phosphate
Good food sources of calcium?
Dairy, sardines, almonds, flaxseed, leafy greens
Calcium absorption happens in the small intestines. Excess of what may reduce absorption?
Fibre, particularly wheat bran and supplements
Major function of calcium?
Bone mineralisation and formation
(also involved in blood clotting, nerve transmission, cell signalling/function)
Factors increasing demand for calcium?
- digestive disorders
- high intake of tannins inhibits absorption
- high sodium intake
- alcohol
Calcium deficiency signs/symptoms
- fatigue
- muscle aches/cramps
- numbness/tingling around mouth, hands, feet
- nail/skin problems
Signs/symptoms associated with magnesium deficiency?
- leg cramping
- headaches/migraines
- sleep problems
- constipation
- PMS
- irregular heartbeat
Good food sources of magnesium?
Beans and legumes, tap water, nuts/seeds
Absorption of magnesium can be enhanced with vitamin D, lactose and fructose. What can reduce absorption?
Phytate and non-fermentable fibre
Main functions of magnesium?
- energy metabolism (needed for ATP production)
- bone mineralisation
- glucose metabolism
- cardiovascular function
Major function of phosphorous?
Bone mineralisation
(also part of phospholipids)
Major functions of zinc
- blood sugar regulation
- enhance smell/taste
- immunity
- part of many enzymes
- sperm production
- immunity
Zinc deficiency signs/symptoms
- poor appetite
- poor wound healing
- loss smell/taste
- frequent infections
- eczema
- hair loss
Some good food sources of zinc
- protein-containing foods (red meat, shellfish)
- wholegrains
- fortified cereals
Major function of chromium?
blood sugar regulation
Haem iron is more readily absorbed (25%) than non-haem iron (17%) - what factors can enhance iron absorption in general?
- MFP factor (peptide in animal products)
- Vitamin C
- Citric acid and lactic acid
- HCL in stomach
- Sugars (esp. fructose)
Main function of iodine
Thyroid hormones (help regulate metabolism, growth and development)
Main function of fluoride
Bone and teeth health
What does the DASH diet stand for?
Dietary approaches to stop hypertension
What is the DASH diet high and low in?
High: calcium, potassium, magnesium (protein, fibre, low-fat dairy)
Low: sodium, saturated fat and sugar
What’s the FODMAP diet and what it is good for?
Fermentable oligosaccharides, disaccharides, monosaccharides and polyols
A group of carbohydrates that may not be digested properly
Good for managing common digestive symptoms like in IBS
Some benefits of the Mediterranean diet
- better cardiovascular health outcomes
- lower rates of obesity and diabetes
- lower rates of cancers and alzheimers
- better quality of life
Olives/EVOO/oleocanthal/oleuropein protect against what?
CVD, dementia, type 2 diabetes, cancer
Resveratrol/red wine/grapes protect against what?
Cancer, ageing, neurodegeneration
Oily fish/omega 3 fatty acids protect against what?
Anti-inflammatory, heart disease, arthritis, depression, inflammatory bowel disease
Phytonutrient resveratrol is found in…?
Grape skins
Epigallocatechin gallate is an antioxidant found in…?
Green tea
Cinnamic acid is found in cinnamon and has what properties?
Anti-diabetic properties
Anthocyanins are found in what foods?
Blueberries (blue/purple foods)
> antioxidant and protect against CVD
Quercetin is flavonol; an antioxidant, anti-inflammatory and anti-histamine. Name some foods it’s found in.
Black tea, berries, onions, citrus fruit, broccoli
What are some examples of lifestyle strategies?
Bring a water bottle with you, pack lunch, cook, relax, etc.
