Aani CP: Nutrition and metab Flashcards
Where is Vit A stored?
Adipose tissue (fat soluble). Vit A is Retinol
What is Retinol?
Vit A
What can lack of retinol (vit A) cause?
Rod production impaired: Colour blindness or night blindness
Bitot’s spots
Dry hair and skin
How do you test for Vit A deficiency?
Serum Vit A/Retinol levels
What can excess Vit A cause?
Exfoliation hepatitis
What is Vit D? (another name)
Cholecalciferol
What can Vit D deficiency cause?
Rickets/osteomalacia
How do you measure Vit D deficiency?
Serum levels of pre-activated (25,hydroxyvit D)
What causes Pallegra?
Vit B3 deficiency (Niacin)
What is Niacin?
Vit B3
How do you cure Wernicke Syndrome?
Pabrinex
What can be caused by low B1 (thiamin)?
Wernicke’s encephalopathy Syndrome: triad of confusion, ophthalmoplegia, ataxia
Beri Beri - wet or dry. Wet: oedema, cardiomegaly, dyspnoea. Dry: Ascending neuropathy
Kosafoff’s Syndrome: Irreversible confabulation, memory loss, lack of insight
What is Vit B6?
Pyridoxine
What can be caused by low B6/Pyridoxine?
Seborrhoeic Dermatitis
Sideroblastic Anaemia
Can be caused by TB treatment with izoniazid
What can lack of Vit K cause?
Defective clotting/bleeding: ecchymosis, petechiae, haematomas, slow healing wounds
How can you test for Vit K deficiency?
PT or INR
What can low Vit E cause?
Haemolytic Anaemia
Increased risk of IHD
Areflexia & Ataxia
What can low B3/Niacin cause?
Pallegra (4 Ds Diarrhoea/Dermatitis/Dementia/Death)
Dermatitis: Casal’s necklace distribution
What is pallegra? How is it caused?
Caused by lack of B3/Niacin - leads to 4 Ds; diarrhoea, dementia, dermatitis. death
Dermatitis: Casal’s necklace distribution
MALNUTRITION (esp protein)
Need a deficiency in niacin AND tryptophan for Pallegra to ensue because tryptophan can be converted into protein
How to test for B1/thiamin deficiency?
RBCs or Transkelotase
What is Vit B2?
Riboflavin
What can low Vit B2/Riboflavin cause?
Glossitis, angular stomatitis, corneal ulceration
How to test for Low B2/Riboflavin?
RBCs and glutathion reductase
How do you test for low B6/Pyridoxine?
RBC AST activation
What is Vit B12?
Cobalamin
What can low Vit B12 cause?
- Pernicious Anaemia –> megaloblastic anaemia with hypersegmented neutrophils
- Degeneration of the cord –> babinski sign +
- Ass. with other autoimmune conditions
How to test for B12 deficiency?
Shilling test, serum b12
What is Vit C?
Ascorbic Acid
What can low Vit C/Ascorbate cause?
Poor collagen formation due to inability to make helices Scurvy: gingivitis bleeding in skin, joints, gums Brittle bones
What can excess Vit C cause?
Renal stones
What can low folate cause?
Megaloblastic anaemia
SACDC (neural tube defects)
Beefy tongue
Peripheral neuropathy
What can low iron cause?
Hypochromic anaemia/microcytic
Excess iron can cause…?
Haemochromatosis - liver damage, pancreas failure etc
Testing for iron deficiency?
Serum Iron
FIBC/transferrin
Ferritin
FBC
What can low iodine cause?
Hypothyroidism
Goitre
Low Zinc can cause…?
Dermatitis
Low Copper can cause…?
Anaemia
Excess copper can cause…?
Wilson’s disease
How do you test for coopper levels?
Caeruloplasmin
What can low fluoride cause?
Dental caries
What are the 4 key Gurthrie test conditions?
Phenylketouria
Hypothyroidism
CF
MCADD
What is Phenylketouria? What happens?
Deficiency in Phenylanaline Hydroxylase. That is needed to breakdown phenylanaline which is toxic. You get an increase is phenylanaline
How to test for Phenylketouria?
Measure blood phenylanaline levels
Tx for Phenylketouria?
Give phenylanaline hydroxylase
What is the feature of congenital hypothyroidism?
Agenesis/dysgenesis of the thyroid gland?
How to screen for congenital hypothyroidism?
TSH levels
What causes CF?
Defect in gene coding for CFTR protein (cystic fibrosis transmembrane conductance regulator)
What are the symptoms of CF?
Chest infections
Productive cough
Diarrhoea
Ductal blockages
How to screen for CF?
If immune reactive tripsin is high, look for genetic defects
What is MCAD?
Medium Chain AcylCoA Dehydrogenase Deficiency. Impairment of fatty acid oxidation
What happens in MCAD?
Impairment of fatty acid oxidation. Medium chains cannot be broken down into AcetylcoA
What are the symptoms of MCAD?
Hypoglycaemia
Sudden Death
Screening for MCAD?
Acylcarnitine levels by Mass Spectrometry
Why is ammonia build up bad?
300+ can lead to coma
What are the clinical features of urea cycle disorders?
Respiratory alkalosis
Hyperammonia
Vomiting without Diarrhoea
Why is ammonia raised in urea cycle disorders?
Because the disorders prevent the ammonia from being broken down into urea
Treatment of urea cycle disorders?
Remove ammonia and reduce protein intake
How can you remove ammonia?
Sodium benzoate
What is galactosaemia?
Gal-1-PUT deficiency
What are the clinical features of galactosaemia?
Tx?
Hepatomegaly Cataracts Mental Handicap Conjugated hyperbilirubinaemia - jaundice Vom & Diarrhoea Sepsis Tx: galactose free diet
What happens in galactosaemia?
Cannot break down galactose due to Gal-1-PUT deficiency. So there will be galactose in the urine. Lactose is broken down into glucose and galactose so it is seen when neonates drink milk.
Which organism causes sepsis in galactosaemia?
E.Coli
What is a clue that someone may have a mitochondria disorder?
Multiple systems are affected
Types of mitochondria disorder?
MELAS
Barth
Kearns-Sayre
What is MELAS?
Mitochondrial Encephalopathy Lactic Acidosis and Stroke like episodes
What age does MELAS present?
5-15
What age does Barth present?
Birth
What age does Kearns-Sayre present?
12-30
What is the most recognized laboratory abnormality in patients with mitochondrial disorders?
Lactic acidosis
Why is lactate raised in mitochondria disorders?
Because dysfunction in the electron transport chain causes pyruvate to rise which is turned into lactate
When should lactate be low in normal people?
After fasting
When is lactate high in normal people?
In hypoxia e.g. after exercise
What is the name for Vit E?
Tocopherol
Symptoms of Phenylketonuria?
- Fair hair (sometimes blue eyes)
- Low IQ
- Musty smell/mousy smell
- Tested for in GUTHRIE test
Symptoms of Maple Syrup Urine Disease
TRIAD of:
- lethargy
- poor feeding
- hypotonia
Characteristic maple sweet smell, esp in urine.
SWEATY feet
How does maple syrup urine disease come about?
Inborn error of metabolism of certain AAs:
valine
leucine
isoleucine
Test for maple syrup urine disease?
Gas chromatography and mass spectrometry
Homocystinuria clinical findings?
Brittle hair Hypopigmentation in skin (pale) developmental/learning delay - seizures - skeletal problems , hard to walk etc - eye problems
management of homocystinuria?
- b6 (pyridoxine)
- b12
- folate
- low methionine diet
What happens in homocystinuria?
deficiency of cystathionine beta synthetase enzyme, build up of methionine in plasma and homocystine in blood and urea
Features of Fabry’s?
It’s a lysozomal storage disorder:
- body dismorphia (abnormality)
- CHERRY RED SPOT
- Organomegaly
- developmental delay
Which enzyme is defective in Fabry’s?
alpha galactosidase
What is Vit B9?
Folate
What happens in Tyrosinaemia?
Cannot metabolise tyrosine. There are 3 types. Type 1 common in Canada/Quebec Jaundice, failure to thrive, bloody stool CABBAGE smell Hepatomegaly with liver failure
Which pt groups are encouraged to reduce Vit A consumption?
Pregnant women.
Vit A can be teratogenic
E.g. found in liver (cos stored in liver)