Nutrition Flashcards
list the vitamins and their toxicity
describe all the vitamins, their principle functions and their deficiency diseases
IGNORE THE TABLE ITS THE ANSWER
describe the location, absorption, source, toxicity, deficiency and function of this mineral: fluoride
location
- distributed through ECF
- bound to albumin in blood and tissues
absorption
- rapidly absorbed as it is soluble
- 50% is absorbed after 30 minutes
- excreted through kidneys
- calcium can reduce absorption
function
- not essential
- forms calcium fluorapatite in teeth and bones
deficiency
- increased risk of dental caries
source
- low concentration in food
describe the source, toxicity, deficiency and function of this mineral: sodium
source
- dietary sodium in the form of salt
- 2.54g of salt has 1g sodium
- 4g of salt a day is the RNI ideal, but 6g is the achievable one
function
- maintain ECF volume
- maintain acid base balance
- muscle contraction and nerve transmission
- a third of ATP at rest is used to maintain cellular sodium potassium gradient
- 30-40% is stored on the surface of bone
toxicity
- too much salt leads to hypertension, strokes and heart disease
- increases calcium excretion and can affect bone health
- aggravates kidney problems
deficiency
- excess sweating can deplete salt but the body adapts
describe the source, toxicity, deficiency and function of this mineral: zinc
function
- synthesis of DNA and RNA - therefore for growth and development
- DNA polymerase is zinc dependent
- antioxidant enzyme superoxidase dismutase needs zinc
- structural role
- expression of genes
- immunity
sources
- oysters, meat, liver, wheatflour
DRV
- 102-109mg a day for males and females
deficiency
- growth retardation, immaturity, neuropyschiatric disturbances, dermatitis, alopecia, diarrhoea, appetite loss
- low serum zinc in pregnancy is associated with low birth weight and pre term delivery
supplementation
- stimulates growth and development
- reduces diarrhoea and respiratory infections in children
describe the absorption, forms, source, toxicity, deficiency and function of this mineral: iron
function
- haemoglobin
- ATP production
- oxygen reserve in muscle
- defence against infection via lactoferrin
absorption
- 20-35% of haem iron is absorbed and 1-10% of non haem iron
- spices and tea can reduce iron absorption by 50%
- absorption of haem iron: influenced by amount of haem iron present, enhanced by meat, inhibited by calcium
- absorption of non haem iron: amount of non haem present, iron status and requirements all influence absorption. enhanced by ascorbic acid, meat, fish and seafood. inhibited by phytates, phenolics and calcium
sources
- haem - animal foods like meat and meat products
- non haem - plant foods - cereals, pulses, veg, fruit, egg, dairy
deficiency
- iron deficiency anaemia
- most common nutritional deficiency
- reduced blood cells due to iron deficiency
- ID alone is if it is less than 15-20ug
- IDA is when it is less than 12-13 ug
toxicity
- not an issue in healthy people
- haemochromatosis is an inherited disorder
- supplement overdose: 300mg per kg is lethal, 20 is toxic in children
- supplement overdose in adults:
- 100g is lethal, 45mg a day has adverse effects
describe the source, toxicity, deficiency, absorption and function of this mineral: calcium
roles
- bone health
- peak bone mass at 30-35 (when bones are strongest)
sources
- water, milk, cereals, roots, bread, bones from fish, eggs, pulses, broccoli, parsley
DRV
- 700mg a day
absorption
- 10-30% of dietary calcium is absorbed
- reduced absorption when there is vitamin D deficiency, fibre, or large calcium load
- increased absorption when there are lactose and casein peptides from milk
- increased absorption to match needs like during growth, pregnancy, lactation and if there is low calcium load
deficiency
- severe malnutrition, lack of vitamin D, osteoporosis
- tightly regulated so this does not usually happen
toxicity
- unknown
describe the forms, source, toxicity, deficiency and function of vitamin: K
form
- 2methyl 1,4 nathoquinone
- menaquinones when formed in the gut bacteria
sources
- green leafy vegetables
- formed by bacteria in gut
funtion
- synthesis of prothrombin in the liver
- synthesis of factors VII, IX and X
- needed for coagulation
deficiency
- unlikely
- some children born with sterile guts and are given vitamin K injection at birth
describe the forms, source, toxicity, deficiency and function of vitamin: E
forms
- 8
- 4 tocopherols (alpha, beta delta and gamma)
- 4 tocotrienols (alpha, beta, delta, and gamma)
- most potent is alpha tocopherol
- alpha and gamma tocopherols predominate in a mixed diet
function
- antioxidant, protects cell components from oxidation by free radicals
- regenerated by vitamin C after it has been oxidised
- found in lipid bilayer
- component of plasma lipoproteins that transport cholesterol and polyunsaturated fatty acids
deficiency in infants
- haemolytic anaemia - red blood cells rupture
- thrombocytosis - oedema due to increased platelet count
deficiency in children and adults
- unable to absorb or utilise vitE
- neurological syndrom involving CNS and PNS, deposition of yellow or white pigment in the retina, irregular movement
toxicity
- no adverse effects
sources
- veg oils, fruit and veg, animal products and fortified foods like cereals
DRV
- no DRV because requirement depends on PUFA intake which depends on diet
describe the synthesis, source, form, toxicity, deficiency and function of vitamin:
forms
- D2 is dietary - ergocalciferol
- D3 is cholecalciferol
- 7dehydrocholesterol is vitD made in the skin
- active form is 1,25 dihydroxyvitamin D3
synthesis
- 7 dehydrocholesterol made in skin combines with d2 ergocalciferol from food and supplements
- forms d3 - cholecalfiferol
- cholecalciferol is hydroxylated at the 25 position in the liver and is hydroxylated at the 1 position in the kidney
- this forms 1,25 dihydrovitamin D3
- affected by quantity and quality of UV, latitude, amount of sun exposure and amount of skin exposed
function
- promote intestinal calcium absorption
- repair bone
- cell differentiation
- immunity
- promote cell maturation in small intestine
- insulin secretion
- blood pressure regulation
DRV
- 10 ug of VitD a day
food sources
- fatty fish, eggs, liver
- fortified foods like margarine
deficiency
- rickets in children - bowed legs, lack of mineralisation of bones leads to malformation
- hypoplasia of teeth due to lack of enamel calcification
- osteomalacia in adults - softening of bones, pain in pelvis, ribs, shoulder, waddling gate
toxicity
- most toxic of the vitamins
- 7 dehydrocholesterol is broken down by excessive UV, the toxicity therefore comes from excessive oral intake
- leads to hypercalcaemia, which leads to diarrhoea, thirst, anorexia, calcification of soft tissue and urinary stones
describe the synthesis, source, toxicity, deficiency and function of vitamin: C
synthesis
- synthesised in plants from d glucose and d galactose
- cannot be synthesised in humans
function
- antioxidant
- regeneration of vitamin E
- collagen synthesis, component of gingival connective tissue
- synthesis of noradrenaline from dopamine
- sysnthesis of carnitine from lysine
- synthesis of bile acid
sources
- leafy veg and legumes lose 50% of vitamin C content after 24 hours from harvest
- labile so it oxidises very quickly
- 27% drinks, 19% fruit juice, 8% soft drinks, 15% potatoes and savoury snacks, 19% fruit
deficiency
- scurvy, connective tissue defects
- poor wound healing
- bleeding, tooth loss
- pain and weakness in legs and ankles
- poor bone and cartilage formation
- bleeding from capillaries
toxicity
- absorption threshold is 2-3g a day
- can cause diarrhoea, calcium oxalate stones in urinary tract, excessive absorption of iron
DRV
- based on amount to prevent scurvy
- 40mg a day
- smokers do 80mg a day
- pregnancy in last trimester increase by 10mg a day
- lactation increase by 30mg
describe the forms, source, toxicity, deficiency and function of vitamin: B12
forms
- B12 or cobalamin
- active form consists of porphyrin ring with central cobalt atom
sources
- meat, fish, diary, canned meat, egg white, cheese
deficiency
- iron deficiency and anaemia
- megaloblastic anaemia
- glossitis, apthous stomatitis, atrophy of lingual papilla, burning and redness of the tongue, angular stomatitis, dysphagia, pallor of oral tissues
describe the source, toxicity, deficiency and function of vitamin: folate
source
- leafy green vegetables, liver, yeast
function
- coenzyme for dna synthesis
- protein synthesis from serine and glycine
- formation of red blood cells
- closure of neural tube in pregnancy
toxicity
- none
deficiency
- closure of neural tube in pregnancy
- megaloblastic anaemia - abnormal multilobed neutrophil nuclei giant platelets
- orofacial clefts, oral and pharyngeal malignancies
describe the source, toxicity, deficiency and function of vitamin: biotin
source
- widely available
deficiency
- rare
function
- lipogenesis, gluconeogenesis
- catabolism of branched chain amino acids
describe the source, toxicity, deficiency and function of vitamin: B6
pyridoxine, pyridoxamine, pyridoxal
source
- all foods
- synthesised by colonic bacteria
function
- pyridoxal phosphate is a co factor in many enzymes for protein and amino acid metabolism
- protein synthesis
deficiency
- recurrent oral ulcerations
- halitosis
- gingivitis
- soreness
- discolouration
- cheilitis
toxicity
- sensory neuropathy
- 50-500mg a day
- reversible
describe the source, toxicity, deficiency and function of vitamin: pantothenic acid
source
- mushroom, legume, egg, peanut, milk, offal, avocados
deficiency
- no natural
function
- part of CoA in krebs and fat synthesis
- all metabolism
describe the source, toxicity, deficiency and function of vitamin: niacin
source
- liver, yeast, legumes, meat, peanuts, cereals
- synthesis of tryptophan
deficiency
- pellagra (dementia, dermatitis, diarrhoea)
- glossitis, stomatitis, rash, angular stomatitis, cheilosis
toxicity
- 3-6g a day
- liver failure and peptic ulcers
function
- needed for NAD, essential for metabolism both catabolic and synthetic
describe the source, toxicity, deficiency and function of vitamin: riboflavin
source
- milk, cheese, liver, eggs, offal, leafy green veg
toxicity
- none
deficiency
- rare
- cheilosis lesions, angular stomatitis, fissures on tongue or magenta discolouration
function
- metabolism of fats, ketone bodies, carbohydrates and proteins
describe the source, toxicity, deficiency and function of vitamin: thiamin
source
- cereals, meats, legumes, yeasts
toxicity
- more than 3g a day is toxic
- headache, irritability, insomnia, rapid pulse dermatitis, death
deficiency
- wernicke encephalopathy, beri beri, neurodegenerative and metabolic disorders
function
- co enzyme needed for production of ribose
- metabolism of carbs, proteins and fats
- neural transmission
describe the function of all B vitamins
maximised function when all B vits work together
function
- release energy from carbs and fats (thiamin, niacin, riboflavins, biotin, pantothenic acid)
- catalyse the formation of RBC (B12, folic acid)
- protein and amino acid metabolism (B6)
describe the location, function, deficiency and toxicity symptoms of vitamin: A
two forms
- preformed is found in liver, fatty fish, eggs, dairy
- provitamin A is found in leafy veg, alpha and beta carotenoids
function
- regulates gene expression, rbc production, cell differentiation, tooth and oral epithelial development
deficiency
- low intake can decrease oral epithelial tissue development, impair tooth formation, enamel hypoplasia and presence of periodontitis
- increases susceptibility to infection due to reduced production of mucopolysaccharides, and xerophalmia (increased keratinisation), decreased macrophages and lysozyme activity, antibody function is affected too
- impaired growth and development due to gene expression and cell differentiation impairment, impaired bone growth, infertility in males and low conception rates in females
toxicity
- acute is more than 200mg
- vomiting, headaches, vertigo, uncoordinated muscle movements
- chronic is more than 10mg a day for a month, leads tobone and muscle pain, alopecia
describe the main functions of essential minerals
- constituents of bones and teeth (calcium, phosphorus and magnesium)
- formation of soluble salts which help control composition of bodily fluids (sodium, potassium and chlorine)
- essential components of many enzymes and other proteins, necessary for release and utilisation of energy (iron, zinc)
describe the features of minerals
inorganic elements. 15-16 essential minerals that cannot be produced in the body
major minerals
- iron
- calcium
- zinc
- magnesium
- sodium
- chloride
- potassium
- phosphorus
describe the factors affecting the use of vitamins
- availability
- antivitamins (avidin prevents absorption of biotin, released on cooking)
- provitamins - carotenes converted to vitamin A
- biosynthesis - vitamin K and D
- intestinal disease - coeliac affects B12 absorption
- interactions of nutrients - vit E increased when there is high polyunsaturated fat intake
describe the features of vitamins
- essential to humans because we cannot make them (vitD and vitK excluded)
- to prove something is a vitamin, there has to be abnormal metabolic sign and disease when someone is deprived that is cured when there is restoration of the missing compound
fat soluble vitamins
- found with fat in food, absorbed in lymph, stored in liver and fatty tissues
- A
- D
- E
- K
water soluble vitamins
- absorbed directly into blood, high turnover, little storage, more sensitive to heat, harmful in high doses
- C
- B vitamins:
- niacin
- B6
- riboflavin
- pantothenic acid
- thiamin
- folate
- B12
- biotin
describe the role of hormones during surgery
overall metabolic effect:
- increased catabolism which mobilises substrates to provide energy sources
- mechanism to retain salt and water and maintain fluid volume and cardiovascular homeostasis
hormonal changes
- ACTH increase
- GH increase
- aldosterone increase
- glucagon increase
- insulin decrease
- T3 decrease
discuss control of nutrient metabolism during stress
during stress, the hypothalamic pituitary adrenal axis is activated to regulate many body processes, including energy storage and expenditure
cortisol
- regains glucose homeostasis
- increased blood glucose through gluconeogenesis
- glycogenolysis in liver and muscle tissue by facilitation of the activation of glycogen phosphorylase
- redistributes glucose to areas of the body that need it the most
adrenaline and noradrenaline
- increase fatty acids for ATP production
- trigger intracellular cascade to phosphorylate hormone sensitive lipase to break down TAG of adipose tissue and muscle tissue into glycerol and free fatty acids
- inhibit insulin secretion
- trigger glucagon secretion
- stimulate glycolysis and glycogenolysis
growth hormone
- promote lipolysis and fatty acid oxidation
- reduce liver uptake of glucose and maintain plasma glucose concentration
- promote gluconeogenesis in the liver
discuss the energy metabolism adaptations to starvation and positive energy balance
human metabolic processes can adapt to a wide range of fuel supply by altering fuel selection
lack of energy provided by food will lead to negative energy imbalance and vice versa
starvation
- negative energy imbalance
- switch from carbohydrate to fat metabolism
- stores of liver and muscle glycogen are depleted
- increased gluconeogenesis from amino acids and glycerol
- ketogenesis takes over, metabolic needs met by ketone bodies and free fatty acids
- declined metabolism, bone mass, thyroid hormone deficiency, inability to concentrate, reduced physical performance
positive energy imbalance
- increase of fat storage in adipocytes
- plaque can build up in arteries
- hypertension
- total and LDL cholesterol and TAG increases
- insulin resistance develops which leads to development of T2DM
discuss the role of hormones in protein synthesis and breakdown
insulin is anabolic and stimulates protein production
growth hormone stimulates protein synthesis and acts through insulin growth factor 1 and 2.
testesterone and adrenergic influences can also lead to protein synthesis
insulin
- increases amino acid uptake
- increases protein synthase enzymes and reduces activity of protein catabolic enzymes
discuss the detrimental impact of insulin resistance on fat and carbohydrate metabolism
obesity leads to excess adipose tissue and there is lipid accumulation
consider the central role of insulin in regulation of exogenous and endogenous fat metabolism
fat mobilisation is catalysed by enzyme hormone sensitive lipase and this enzyme is inactive when insulin levels are high due to dephosphorylation
stimulates re esterification by provision of glycerol-3-phosphate
increases activity of lipoprotein lipase activity in adipose tissue, which resides on the capillary endothelium of adipose and muscle tissue. this increased activity provides clearance of TAG from chylomicrons and low density lipoproteins
consider the central role of insulin and glucagon in regulation of exogenous and endogenous carbohydrate metabolism
insulin
- stimulates glucose uptake by cells
- stimulates glycolyses
- stimulates glycogen synthesis
- inhibits glycogen catabolism
glucagon
- released by alpha cells
- increases glycogen breakdown in the liver
- increases gluconeogenesis in the liver
- increases ketone body synthesis
discuss hormonal responses during absorptive and postabsorptive states and their role in regulation of carbohydrates, fat and protein metabolism
hormonal in absorptive state
- increased blood glucose
- increase blood triglycerides
- decreased blood FFA
- decreased betahydroxybutyrate
- increased insulin
- decreased glucagon
hormonal in postabsorptive state
- decreased blood glucose
- decreased blood triglycerides
- increased blood FFA
- increased betahydroxybutyrate
- decreased insulin
- increased glucagon
regulation
- insulin regulates all events in absorptive state
- insulin controls glucose uptake by muscle, suppresses FFA release, FFA release from chylomicrons, liver and muscle glycogen synthesis, protein synthesis
discuss the role of endogenous energy substrates in energy metabolism during postabsorptive state
endogenous energy substrates include liver glycogen, adipose tissue, and muscle TAG
the postabsorptive state
- gi tract is empty, energy comes from breakdown of body reserves
- glycogen, tg, and protein synthesis is stopped or very slow
- increased glucose release from liver, lipolysis of TG in adipose tissue is increased
role of lipolysis
- ffa are oxidised to cover the energy demands of muscles
- ffs are used for synthesis of ketone bodies
- glycerol is a substrate for gluconeogenesis
liver glycogen
- first available store of glucose
- blood sugar levels maintained for four hours
- gluconeogenesis is activated in the ilver and glucose is synthesised from lactate, pyruvate, glycerol and amino acids
describe the role of sugar transporters in nutrient absorption
glut
- passive transporters
- 12
sglt
- sodium glucose transport family
- active transport
- move glucose from low to high concentration
regulated by dietary carbohydrate availability
describe lactose intolerance
loss of lactase enzyme when weaning, meaning lactose is not hydrolysed in digestion. it is metabolised to short chain fatty acids.
diagnosed by hydrogen in the breath due to lactose malabsorption.
discuss primary and secondary risk factors for nutritional deficiences, including impaired nutrient digestion, absorption and transport
primary deficiency
- inadequate selection of food
- age, income and education
secondary deficiency
- systemic disorders that can affect digestion, absorption, transport and use of nutrients
- crohsn, CF, bariatric surgery, renal and hepatic disease
discuss why nutrition knowledge is important to dentists
nutrition has a key role to play in dental health
can affect dental caries, periodontal disease, gingivitis.
issues within the body due to nutrition and present in the mouth by looking at corners of the mouth, tongue, palate, and teeth
nutrients required for dental health
- calcium
- phosphorus
- vitamin A, C, D
- fluoride
nutrients that are bad for dental health
- carbohydrate
- sweet foods
- sugars
- fruit and carbonated drinks
vitamin D deficiency and oral health
- needed for mineral density
- helps absorb, carry and deposit calcium in the bones supporting teeth
- associated with caries and periodontitis
role of nutrition in oromaxillofacial
- oral disease surgery and injury can affect food and fluid intake which compromises nutritional status
discuss dietary reference values for protein, carbohydrate and fat in the UK diet
carbohydrates
- 4kcal per gram
- 47% of total energy intake, 50% of total food intake
fat
- 9kcal per gram
- 33% of total energy intake, 35% of total food intake
protein
- 4 kcal per gram
- 15% of total energy intake, 15% of total food intake
alcohol
- 7 kcal per gram
- included in carbohydrate DRV
discuss health implications of free sugar overconsumption
all that is added or found in honey and fruit jucice
adults
- obesity
- caries
- poor diet diversity
- incresed risk of T2DM and CVD
children
- less than 5% is ideal
- sugar should be part of a main meal
describe what happens to non starch polysaccharides
they absorb water in the gi tract and provide fuel to bacterial metabolism
they are fermented in the colon to produce short chain fatty acids that are metablised in various parts of the body
SCFA include
- acetic acid - 2c
- propionic acid - 3c
- butyric acid - 4c
discuss the fate of macronutrient digestion products in absorptive state
- absorptive state is the time during and right after a meal
- lasts for four to six hours
- end products of nutrient digestion undergo anabolic processes leading to nutrient storage in the form of TAG and glycogen
- most amino acids are used for protein synthesis
fate of glucose
- adipose tissue
- liver contains 400kcal - 100g glycogen
- muscle contains 1600kcal of glycogen - 400g glycogen
- upper limit of glycogen is 1050g
fate of triglycerides
- released from chylomicrons by lipoprotein lipase and ATP synthesis using exogenous and endogenous fat
fate of amino acids
- liver - ATP and protein synthesis
- muscle and all other cells - amino acids form proteins
explain the role of the pancreas and liver in digestion
pancreatic amylase and pancreatic proteases are important for the digestion of carbs and proteins.
liver metabolises and detoxifies molecules absorbed from digestion.
liver produces bile acids which are required for fat digestion as it is an emulsifying agent.
describe the digestion of carbohydrate, fat and protein and the roles of different enzymes in the digestion of starch, sugars, proteins and fats
digestion is through hydrolysis - major macronutrients are digested in this way. requires alpha amylase.
starch polysaccharides are broken down by salivary and pancreatic amylase to become di and tri saccharides which are broken down by maltase, lactase, sucrase and isomaltase produced from the intestinal surface villi. these become monosaccharides like glucose, galactose and fructose.
- mono and disaccharides are absorbed in small intestine as monosaccharides
- oligosacchardies are digested in large bowel and are absorbed as short chain fatty acids
- polysaccharides if starch are absorbed as glucose, as non starch they are absorbed as short chain fatty acids
- maltase breaks down maltose to two glucose molecules
- sucrase breaks down sucrose into glucose and fructose
- lactase breaks down lactose into glucose and galactose
- starch becomes maltose in the oral cavity which then becomes two glucose molecules
digestion of fats
- emulsification by bile acids forms micelles
- pancreatic lipase hydrolyses TAG and forms 2-monoglycerol
- fats need emulsification to be digested as enzymes are aqueous and fats are hydrophobic
- fatty acids are absorbed at the brush border by diffusion.
- if they are more than 12 carbons long the fatty acids become chylomicrons and enter the lymphatics before entering the blood
- chylomicrobs have TAG and cholesterol esters in their core, and their surface is made up of phospholipids, apoproteins, and unesterified cholesterol
digestion of proteins
- HCl and pepsin in the stomach to break down 20% of proteins into amino acids
- hydrolysed in the lumen of the small intestine into oligopeptides
- relies on pancreatic proteases like trypsin, chymotrypsin and carboxypeptidases
- peptidases and oligopeptidases are intestinal surface enzymes that then break down the peptides into amino acids
- amino acids are absorbed via sodium cotransporters
- peptides longer than 4 amino acids long are not absorbed and must be broken down
discuss macronutrients, their classification and functions
carbohydrates
- monosaccharides
- disaccharides
- polysaccharides
- sugars
- dietary fibres are non starch polysaccharides that absorb water in the GI tract, increasing transit time and causing faecal bulking, are fuel for bacteria metabolism
- inulin and oligofructose are prebiotics as they stimulate growth and activity of health stimulating intestinal bacteria. found in chicory roots, jerusalem artichokes and garlic.
- dietary carbs fate: glucose uptake by muscle, liver and muscle glycogen synthesis, disposal of glucose in muscle
proteins
- long chains of amino acids bound by peptide linkages
- must be digested into amino acids or di/tripeptides
- HCl denatures proteins, activates zymogen pepsinogen so it can become pepsin and break down 20% of the proteins.
fats and oils
- fats are solid at room temp oils are liquid
- fats are dietary triglycerides, major form is water insoluble lipids
- main dietary lipids: triglycerides are glycerol+3FA
phospholipids are phosphorus+2FA
sterols are derived from fatty acids, include cholesterol
macronutrient functions
- provide energy in sufficient quantities
- provide range of building blocks
- provide essential nutrients we cannot make ourselves
