Nutrition Pharmacology Flashcards
Describe the Eatwell guide:
1/3 fruit and veg (5 variety)
1/3 starch, potatoes, bread, pasta= wholegrain
Some protein, lean meat/fish, plant protein
Dairy
Small amounts of oils and spreads
6-8 glasses of water a day
Why are there different nutrient requirements for different people?
Age- exercise less as older
Gender- men have increased muscle mass
Physiological state e.g pregnant
Genotype- everyone has different, so affects metabolism
Environmental e.g smoking increases pro-oxidants so take vitamin C (antioxidant)
What are the different dietary reference values?
RNI=reference nutrient intake
EAR= estimated average requirement
SI=safe intake
What is RNI?
Amount of a nutrient that is enough to ensure that the needs of nearly all the group (97.5%) are being met i.e most require less
What is EAR?
Estimate of the average requirement for energy or a nutrient, approx 50% group of people require more, 50% require less
What is the food labelling process for nutrients?
GDA- guideline daily amounts- traffic light system
Describe the need for infant nutrition:
Nutritional requirements are high due to rapid growth and development
Breast milk best form of nutrition in first 6 months, formula milk provides the same nutrition however in breast milk, particularly in the first days (colostrum) secretes IgA antibodies with protects GIT
What is infant formula and describe the different ones?
It is cows milk to mimic breast milk
New born-birth to 1 year:
-SMA Pro or Cow and gate first infant milk
-SMA extra hungry- different type of protein which satisfies them more
Follow on 6months-1year, has increased iron:
-SMA pro or C&G Follow on
Toddler milk 1-3 years:
-SMA pro toddler milk
What are the different type of prescribable infant formula and what are they used for?
Soya based- cows milk protein allergy
e.g SMA soya, Infasoy, concerns with using before 6 months as soya can be allergenic as IS not fully developed
Extensively hydrolysed formula- modified cows milk, hypoallergenic (with lots of different allergies)
e.g Althera, Nutramigen
Others including lactose free, anti-reflix, high energy
Which foods would you avoid when weaning and why?
Wheat/gluten, fish/shellfish, fruit juices, soya, eggs (before 6 months) due to increased risk of allergy
Salt, sugar, honey (before 1 year)
Care with textures to avoid choking
What are the feeding/ nutrient requirements for pre-school children?
Requirements vary according to size and growth
Small appetites so nutrient dense foods
Whole milk until 2 years
From 2+ should encourage healthy eating guidance
What are the common problems faced with preschool children regarding nutrition?
Faddy eating
Toddler diarrhoea
Constipation
Anaemia
Dental caries
What are the nutrient requirements in adolescents?
Growth spurt
Peak bone mass occurs so Ca and Via D requirements, increase physical activity
Energy and nutrient requirements in boys are greater
Growth spurt begins at around 10 for girls and 12 in boys, can vary greatly
Iron requirements increase in girls after onset of menstruation and continue to be higher until menopause
What are the energy requirements for adults?
M= 2772kcal per day
F=2174kcal per day
Depends on physical activity
What are the protein requirements in adults?
RNI= 0.75g protein per kg body weight
What are the carb requirements for adults?
50% of total energy, <5% of total CHO- free sugars
30g/day fibre
What are the fat requirements for adults?
35% total energy, 11% of total as saturated, increase in omega 3s
What are the alcohol recommendations?
No more than 14 IU a week
Spread evenly over 3 days
Heavy drinking once or twice a seek increase risk of death for long term illness
Risk of developing cancers increase more you drink on regular basis
What are the energy requirements in pregnancy?
Increase by 200kcal in final trimester
Small increase in protein (6g/day)
For lactation, larger increase in protein (+11g)
Avoid shark, sword fish, marlin and tuna
These are long lived fish which contain methyl mercury which is teratogenic
What are the micronutrient requirements in pregnancy?
400µg folic acid a day in first trimester- after this the baby has fully developed
Iron rich foods and possible supplements needed, particularly in last trimester as increase in blood volume
Avoid Vit A supplements and liver as teratogenic
No alcohol, limit caffeine, stay active
What are vitamins?
Organic compounds required in small amounts for normal functioning of the body
They can’t be synthesised
Name the fat soluble vitamins and how long are they stored in the body?
A (retinol)- 6-10 months
D (ergocalciferol)- 2-4 months
E (tocopherol)
K- 1-2 weeks
Name the water soluble vitamins and how long are they stored in the body?
C (ascorbic acid) 2-4 weeks
Folic acid 1-3 months
B3- 2-4 weeks
B1 (thiamine)- 1-2 weeks
B2 (riboflavin) - 1-2 weeks
B6 (pyridoxine) 1-2 weeks
B12 3-6 years (found in animal products)
Panthothenic acid
Niacin
Biotin
What are minerals and trace elements and how much do you need of each and give examples:
Inorganic compounds
Minerals, more than 100mg day e.g Ca, Mg, P
Trace elements, less than 200mg day e.g Fe, Cr, F, Zn, Se
What are the functions of minerals and trace elements?
Structural- bones and teeth e.g Ca, Mg, P
Components of biological fluids e.g Na, K
Nerves and muscles e.g Ca
Iron requirements for carrying O
Osmotic balance e.g Na, Cl
Enzymes (co-factors) e.g Mn,Cu,Fe
Hormones e.g I for thyroxine
How are water soluble vitamins absorbed and describe an exception:
Passively
Except B12
Which requires intrinsic factor for receptor- mediated endocytosis in the terminal ileum
How are fat soluble vitamins absorbed?
Carried in micelles and absorbed passively with end products of fat digestion (mono glycerol/fatty acids)
Ca (2º messenger) and Fe (pro-oxidant) are tightly regulated as don’t want too much free
What vitamins are important for energy metabolism?
All B vitamins
What vitamins are antioxidants?
A (provitamin beta carotene)
C (most potent)
E
Zn, Se, incorporated into cellular antioxidants
What are the essential functions of iron?
Essential for aerobes
Hb
Myoglobin (muscle)
Cyp450
Catalase
Peroxidase
Cell growth and differentiation
What is iron stored as?
Ferritin/ haemacitrin
How is iron absorbed and transported?
Fe is absorbed into cell as ferritin (not absorbed into blood) or if needed can be transported out of the cell by ferroportin into the BS where it is bound to transferrin
After time the ferritin is lost in the faeces as the epithelial cells of the gut is shed
Name and give examples of the two different sources of iron:
Haem- red meat, fish, poultry
Non haem- plant food e.g lentils, beans, iron
What can non-haem iron absorption be increased by?
Taking it with vitamin C in the same meal, as it decreases ferric iron (Fe3+) into Fe2+
What can non-haem iron absorption be decreased by?
Phytates, tannis (tea), Ca, soy
What are the RNI values for iron?
8.7mg/day in males
14.8mg/ day in females
What does anaemia look like under a microscope?
Hypocrhomic (pale) microcytic (small) RBCs compared to normal
In which populations are iron deficiencies normally found?
Women (child bearing age and pregnant), premature and LBW infants, older infants and toddlers and teenage girls
Pts with kidney failure, chronic malabsorption, GI disease
Vit A deficiency limits use of iron stores
What are the symptoms of iron deficiencies?
Pallor (pale), tired and weak, poor work performance
Chronic can leads to slow cognitive and social development in childhood
Decreased immunity
HF if severe anaemia
Describe the treatment for iron deficiency:
Ferrous salts (fumarate, sulfate, gluconate)
Ferric iron
Amount absorbed decreases with increasing doses, therefore often 3 equally spread doses/day
What are the side effects of iron preparations?
GI
N&V
Constipation
Diarrhoea
Start with half dose
Describe the different types of chronic iron toxicity:
Thalassemias- large group of genetic disorders of globulin chain synthesis where blood transfusions required often
Haemochromatosis- genetic iron storage disease
What is the treatment for chronic iron toxicity?
Iron chelators e.g desferrioxamine- complex with ferric iron (makes iron unavailable and removed from body)
Deferiprone (thalassaemias) and deferasirox but more SEs
What is a nutraceutical?
A food or ingredient that provides medical/ health benefits, can be dietary supplements or functional foods
What is a dietary supplement?
Concentrated source of nutrient or other substances with a nutritional or physiological function, in addition to normal food
What are features of functional foods to make them better?
Naturally nutrient rich e.g tomatoes (lycopene decrease risk of prostate cancer)
Medicinally active e.g garlic
Increase conc of active ingredient e.g fortified
Add component that isn’t normally present e.g polyunsaturated FA
Eliminate/ decrease a component
Replace a component with one with known benefits
Increase bioavailability/ stability
Genetically modified
Name different types of antioxidants:
Vits A,C,E
Se, Zn
Cartenoids
Flavonoids
What are the functions of antioxidants?
Counteracting free radicals but also anti-inflammatory, anti-tumorgenic, anti-coagulant, anti-aging
What is omega 3 and what are the benefits?
Mainly fish oils
Eicosapentaenoic acid/ docosahexaenoic acid
Effects on skin and inflammatory mediators- produce resolving mediators
What are phytosterols and give examples:
Plant stannous and sterols
E.g margarines, mayonaises, veg oils, milk, soy, orange juice, snack bars
What are the functions of phytosterols?
Lower absorption of cholesterol as competitively compete with cholesterol
2g daily portion to decrease LDL
What are the functions of probiotics?
Live non pathogenic MOs that when administered in adequate amounts confer a health benefit
Resistant to acid digestion
Advocated for a range of immune and GI disorders
What are factors influencing the effects of supplements?
Genetics (metabolism)
Interactions (nutrients and drugs)
Adverse effects
Bioavailability
Active from
What are the type of studies used in researching the effects of supplements?
Lab studies- in vitro and ex vivo
Animal studies
Observational
Random control test
Prospective cohorts
What are the most common symptoms of malabsorption syndromes?
– Weight loss/failure to thrive
– Abdominal distension
– Diarrhoea
Name the compartments of the small intestine absorption:
– Pancreas secretes digestive enzymes
– Liver secretes bile acids
– Surface area - mucosal folds, villi, microvilli
– Brush border enzymes
What are the most common causes of malabsorption syndromes?
– Western – coeliac disease
– Developing – parasitic and worm infestation
What is coeliac disease characterised by?
Autoimmune disease of small bowel
– Atrophy of small intestinal villi due to abnormal sensitivity to gluten
– Malabsorption of nutrients by the damaged area of the small intestine
– Prompt clinical and histological improvement following gluten withdrawal from diet
What does coeliac disease look like under the microscope?
Endoscopic: Scalloping of mucosal folds
Microscopic (biopsy): Flattened villi
What is the epidemiology of coeliac disease in terms of person?
True prevalence unknown – many with mild or no symptoms - only approx 10-15% diagnosed
UK has high incidence (1/100)
Incidence in females is slightly higher than males
Diagnosed at any age but particularly:
– 8-12 months when children first weaned onto gluten- containing foods
– Third to fourth decades and beyond
What is the epidemiology of coeliac disease in terms of location?
Most prevalent in western Europe and emigrants (USA, Australasia) and Jews
Incidence between 0.05% to approx 1.2 % worldwide
Rare in Africa, Far East and Caribbean
Increasing in India, Middle East and Saharawui population
What is the aetiology of coeliac disease?
– Consumption of gluten proteins
– Genetic predisposition:
- >95% patients express HLA-DQ2 or DQ8
-Receptors they encode bind gliadin peptides more tightly, activating T lymphocytes and initiating autoimmune response
-75% concordance among monozygotic twins
-Up to approx 20% of first degree relatives affected
-Increased risk in Type 1 Diabetes, Down Syndrome, Turner’s syndrome, autoimmune thyroid disease and dermatitis herpetiformis
What is Dermatitis herpetiformis?
Gluten sensitivity
Chronic skin rash that involves limbs, trunk and scalp. Characterised by blisters (up to 1 cm diameter) filled with watery fluid - intensely itchy
Accompanied by intestinal damage (possibly asymptomatic) indistinguishable from coeliac disease
How can you help prevent/ treat Dermatitis herpetiformis?
Gluten-free diet leads to regression of both intestinal and skin symptoms plus dapsone (di-aminodiphenyl sulfone)
What is the pathophysiology of coeliac disease?
Consumption of gluten:
– Gluten proteins sometimes incompletely digested
– Peptides are extremely immunogenic to affected patients
– Prolamines- alcohol soluble fractions of gluten absorbed in small intestine and presented to APC in lamina propria, resulting in immune response in mucosa
What types of food can flare coeliac disease?
Gliadins in wheat
Hordeins in barley
Secalins in rye
Possibly avidins in oats
What are common signs and symptoms of coeliac disease?
– Diarrhoea
– Fatigue
– Borborygmus
– Abdominal pain
– Weight loss
– Failure to thrive
– Abdominal distension
– Flatulence
What are more uncommon/ rare symptoms of coeliac disease?
– Osteopenia /osteoporosis
– Abnormal liver function
– Vomiting
– Iron-deficiency anemia
– Neurologic dysfunction
– Constipation
– Nausea
How would there be a differential diagnosis of coeliac disease compared to IBD?
Restricted to mucosa of small bowel so can differentially diagnose from inflammatory bowel diseases
What are the serological tests to diagnose coeliac disease?
–Tissue transglutaminase (tTG) antibodies
–Endomysial antibodies
–Total IgA antibodies if either of these negative but suspected disease
What are the endoscopic tests to diagnose coeliac disease?
– Macroscopic changes possibly visible eg scalloping
– Biopsy required to confirm diagnosis
What is the morbidity like in coeliac disease?
Rarely lethal
Increased risk of malignancy:
– Most often T cell lymphoma of small bowel – 3-6x risk
– Adenocarcinomas of the GIT – pharnyx, oesophagus, SB
Untreated pregnant women have increased risk of; miscarriage, baby with congenital malformation
Short stature and malnutrition if undiagnosed in childhood
What is the treatment for coeliac disease?
Removal of gluten from diet
What are the causes of undernutrition?
Reduced food intake
Decreased absorption
Decreased activity of co-factors eg intrinsic factor and vitamin B12
Increased metabolism
Underlying disease
What are the physical symptoms of malnutrition?
– Impaired immune function
– Delayed wound healing
– Decreased muscle strength and fatigue
– Hypothermia
– Reduced respiratory muscle function and cough pressure, predisposing to chest infections
– Immobility predisposing to venous thrombosis and embolism and pressure sores
– Reduced final height in women leading to reduced pelvic size and small birth weight infants
What are the psychological and behavioural symptoms of malnutrition?
Depression
Anxiety
Reduced will to recover
Self-neglect
Poor bonding with mother and child
Loss of libido
What is acute protein energy malnutrition in children?
Acute inadequate nutrition leading to rapid weight loss or failure to gain weight normally
What is chronic protein energy malnutrition in children?
Inadequate nutrition over long period of time leading to failure of linear growth
What does wasting mean in a child?
Due to acute:
Thinner than normal, but normal height
What does stunted mean in a child?
Due to chronic:
Shorter than normal, but normal weight
What is the consequence of acute and chronic protein energy malnutrition in a child?
Both wasted and stunted
What is the cause of anorexia nervosa in older adults?
Common, particularly in institutionalised
– PEM and micronutrient deficiencies
– Decreased GI function with reduced absorption or metabolism
– Underlying disease and interaction with drugs
– Reduced intake possibly due to:
* Dysphagia
* Poor appetite
* Poor mastication
Name some examples of diseases where cachexia is common:
Cystic fibrosis
IBD
AIDS
Cancer
Congestive heart failure
COPD
Severe schizophrenia
Drug addiction
Name prescribable supplements which can be supplemented in the form of a drink:
Ensure (Plus) (Abbott)
Fortisip (Nutricia)
Fortimel (Nutricia)
Fresubin (Fresenius)
Enlive (Abbott)
All milk tasting apart from Enlive which is fruit juice tasting
Name prescribable supplements which can be supplemented in the form of a powder to add to food:
Maxijul (Nutricia):
Glucose powder, add to hot/cold drinks, soup, desserts. Not suitable for people with diabetes
Pro-Cal (Vitaflo):
Fat and protein based powder, add to hot/cold drinks, soups, desserts
Calogen (Nutricia):
Fat based liquid, take in small measures as prescribed or add to food e.g. soup, mashed potato, milk pudding
Forticreme (Nutricia):
Mousse style dessert
What is a Jejunostomy?
In the small intestine
If unlikely to resume full oral intake after abdominal surgery or laparotomy
What are the advantages of the nasal feeding route?
Not invasive
Quick
Cheap
What are the disadvantages of the nasal feeding tube?
Irritation
Risk of sinusitis, oesophagitis Dysphagia
Risk of misplacement
Risk of reflux
Easy tube movement or removal
Regular tube replacement
X-ray confirmation
Stigmatising- can see it
What are the advantages of an abdominal feeding tube?
Less stigmatising
Less tube migration
Less tube removal
Less reflux
No nasal irritation
No dysphagia
No tube replacement
What are the disadvantages of an abdominal feeding tube?
Invasive
Sedation and antibiotics
Irritation at site
Leakage into abdomen
Translocation of bowel
X-ray confirmation
Tube clogging
Hematomas causing bowel occlusion
When is nasogastric (enteral) feeding needed?
Short term feeding of <14 days
Unable to take any nutrition orally e.g. stroke, upper GI surgery OR additional nutrition to improve an inadequate intake, eg burns, cystic fibrosis.
What are the common problems of enteral feeding?
Diarrhoea – temp of feed / rate / check date / fibre
Constipation – fluid balance / fibre
Vomiting – rate of feed/ position of pt/ infection?
Blocked tube – feed / meds / not flushed
What type of parietal feed is suitable for most?
Standard polymeric 1kcal/ml
Osmolite, Jevity
What type of parietal feed is suitable for high energy requirements/ volume restriction?
High energy 1.5kcal/ml
Osmolite 1.5Cal, Ensure Plus, Jevity Plus, Jevity 1.5kcal/ml
What type of parietal feed is suitable for long term feeding, helps normalising bowels?
Fibre added
All the Jevity feed varieties
What type of parietal feed is suitable for ascites/ hypertension?
Low sodium
Nutrison low sodium
What type of feed is suitable for renal impairment/ fluid restrictions?
Low electrolyte, energy dense feed
Nepro
What type of feed is suitable for malabsorption, Short Bowel, Crohn’s?
Elemental/ Peptide
Perative
Can partially hydrolysed milk be used for a patient with a cows milk allergy?
No as its still cows milk, just not fully broken down
Commonly used for digestive enzyme problems
What should you take iron supplements with to increase absorption?
With vitamin C to make it readily available absorbed
What does borborygmus mean?
Bowel sounds
