Vitamin Deficiency Flashcards
summarise each vitamin, its site of absorption and the deficiency syndrome?
what is the active form of vitamin A?
Retionic acid
where is vitamin A found ?
liver, kidneys, butter, egg yolks, leafy vegetables
what is the deficiency syndrome for vitamin A?
XEROPHTHALMIA (ocular manifestations)
Abnormal dryness of conjunctiva and cornea of the eye with inflammation
outine the pathophysiology of vitamin A deficiency?
Vitamin A is required for formation of rhodopsin, photoreceptor pigment in the retina so important for vision. It is also important for antioxidation, gene transcription, differentiation of epi cells into specialised tissue and prevent squamous metaplasia (hence prevent formation of Bitot spots)
Deficiency can be due to inadequate intake, fat malabsorption or liver disorders (liver stores vit A)
In xerophthalmia, there is dryness of the conjunctiva and cornea due to keratinisation of the eyes. Conjunctivae develop oval/triangular spots (Bitots spots), and cornea becomes cloudy and soft.
what are the risk factors/causes of vitamin A deificency?
inadequate intake
fat malabsorption
liver disorders ( liver stores vitamin A)
summarise the epidemiology of vitamin A deficiency?
common in southern and eastern asia where rice is staple food- rice is completely lacking beta carotene ( precursor to vitamin A )
Rare in the uK
What are the presenting symptoms of vitamin A deficiency?
Starts off with night blindness
As diseases progresses, cornea becomes hazy and can develop erosions which can lead to its destruction 🡪 complete blindness.
Can also get drying, scaling and follicular thickening of the skin due to keratinisation of skin
Respiratory infections due to keratinisation of mucous membranes in respiratory tract.
what are the clinical features of xerophthalmia?
dryness of the conjuctiva and cornea due to keratinisation of eyes
conjuctiva develop oval/ triangular spots ( Bitot spots)
cornea becomes cloudy and soft
what are the signs of vitamin A deficiency?
Night blindness, which may cause injuries
Bitots spots on conjunctiva
Corneal xerosis – cornea appears dry and dull
Corneal ulcerations
Keratomalacia – last stage of xerophthalmia - softening of cornea, followed by perforation of eyeball and blindness
Dry skin
Dry hair
More prone to infection
what are the appropriate investigations for vitamin A deficiency and interpret the results?
Check sight in darkness
serum renitol binding protein
zinc levels- zinc deficiency can interfere with production of retinol binding protein
iron studies - can affect metabolism of vitamin A
FBC- for anaemia or infection
Generate a management plan for vitamin A deficiency
Treat with vitamin A supplements
Re-educate and monitor diet
High vit A: chicken, eggs, leafy green veg
Identify the possible complications of vitamin A deficiency
Blindness
Respiratory infections
Summarise the prognosis for patients with vitamin A deficiency
Good if treated early, before blindness progresses
What is the deficiency syndrome for B1 ( thiamine)?
Beri Beri-> can lead to Wernicke’s encephalopathy
what systems can be affected by a B1 ( thiamine) deficiency?
Cardio, MSK, GI and nervous system can be affected
What are the risk factors for B1 ( thiamine) deficiency?
Diets consisting of high levels of milled rice and raw freshwater fish
High consumption of tea, coffee and betel nuts
Alcoholic state
Starvation state
Prolonged vomiting
Gastric bypass surgery – due to limited caloric intake post surgery
Parental nutrition without adequate thiamine supplementation
What are the 2 main types of beriberi?
Dry beriberi
Wet beriberi
what are the features of dry beriberi?
Thiamine deficiency with nervous system involvement
Usually occurs with poor caloric intake and physical inactivity
Involves peripheral neuropathy
Wernicke encephalopathy and Korsakoff syndrome are forms of dry beriberi
What are the features of wet beriberi?
Thiamine deficiency with cardiovascular involvement
First, peripheral vasodilation occurs causing high CO. This leads to salt and water retention via RAAS. As vasodilation progresses, kidneys detect relative loss of volume and therefore conserve salt. Salt retention causes fluid absorption into vessels, hence oedema.
The high cardiac workload results in heart failure with general oedema.
summarise the epidemiology of B1/ thiamine deficiency?
Common in alcoholics
More common in developing countries due to malnutrition
what are the symptoms of B1 ( thiamine ) deificency?
EARLY FEATURES: fatigue, apathy, irritability, drowsiness, depression, poor concentration, anorexia, N+V, abdo pain
LATER FEATURES Wet: palpitations, SOB, leg swelling, dyspnoea, orthopnea
LATER FEATURES Dry: numbness of peripheries, confusion, trouble moving legs, pain (cramps)
What are the signs of B1 ( thiamine) deificency?
Tachycardia
Cardiomegaly
Pallor and waxy skin
Signs of malnutrion and wasting
Hepatomegaly
Ankle oedema
Peripheral neuropathy
Depressed tendon reflexes
Loss of vibration sensation
Tender leg muscles
Identify appropriate investigations for vitamin B deficiency and interpret the results?
Diagnosis primarily clinical – high suspicion with chronic alcohol abuse and special diets/malnutrition
Thiamine loading test (rarely performed): administer thiamine and in deficient patients there is less excretion of thiamine than in normal patients.
Red cell transketolase activity is decreased – rarely done
Maybe test blood thiamine level, pyruvate and transketolase level (as the level of these will rise in Wernicke’s encephalopathy)
MRI if Wernicke’s encephalopathy is detected
what is the management plan for b1 ( thiamine) deficiency?
Thiamine (Pabrinex) IV – admin slowly over 10 mins
Oral supplementation to continue after IV
If there is coexisting hypoglycaemia, ensure thiamine given before glucose
Food sources of thiamine: beef, nuts, oats, pork, egg, liver, dried milk, peas and legumes (some foods like rice, pasta, breads and cereals can be fortified with thiamine)
Identify the possible complications of vitamin B deficiency?
Irreversible korsakoff syndrome (chronic memory disorder)
If untreated => HF (which can be fatal)
Anaphalaxis of IV treatment
Summarise the prognosis for patients with vitamin B1 deficiency
Good if treated early, but Korsakoff is minimally reversible
what is the deficiency syndrome for vitamin C?
scurvy
what is the cause of vitamin C deficiency?
inadequate dietary intake
what is vitamin C needed for?
wound healing and immune function and iron absorption
what are the risk factors for vitamin C deficiency?
victims of famine, alcoholics
what are the presenting symptoms of vitamin C deficiency?
Fatigue
Depression
Rash
Internal bleeding, Petechiae
Gingivitis, loose teeth, foul breath
Impaired wound healing
Bleeding from gums, nose, hair follciles or into joints
In children, bone growth may be impaired so gait impairment or leg pain
Anorexia, cachexia
Muscle pain and weakness
Weight loss
Oedema
Joint swelling
what are the signs of vitamin C deficiency?
Rash
Petechiae
Oedema
Cachexia
Follicular hyperkeratosis
Anorexia
What are the appropriate investigations for vitamin C deficiency and interpret the results?
clinical diagnosis
FBC and peripheral smear to look for other haem disorders mimicking scurvy (normocytic anaemia expected)
Serum, whole blood and leukocyte ascorbic acid – should be ordered during initial evaluation to help identify the amount and severity of scurvy
x ray of knee and wrist
what is seen on the x ray of the knee and wrist in a vitamin C deficiency?
Frankel’s sign (lucent line) right below the margin of the growth plate
Wimberger corner fraction sign
trabecular atrophy
Pelkan’s sign
describe a management plan for vitamin C deficency?
Dietary education – broccoli, peppers, spinach, tomatoes, blackcurrant, kiwis, brussel sprouts, strawberries, oranges (other citrus fruits)
Ascorbic acid – 300-500mg/day orally for about 2 weeks and then prevention of vitC def
what are the possible complications of a vitamin C deficiency?
Intracerebral haemmorhage
Endocardial haemorrhage
Neck and back pain
summarise the prognosis of patients with vitamin C deficiency?
GOOD (full recovery) if no haemorrhagic complications occur
define a vitamin E deficiency?
Deficiency of vitamin E (alpha-tocopherol)
outline the aetiology risk factors for vitamin E deficiency?
Can be caused by cystic fibrosis , abetalipoproteinaemia, chronic cholestatic hepatobiliary disease, short bowel syndrome - all affecting absorption
May result from a rare inherited condition called Ataxia with Vitamin E deficiency (AVED)
what is the deficiency syndrome of vitamin E deficiency?
haemolysis and neurological deficit
what are the fucntions of vitamin E?
Vitamin E is an antioxidant; has roles in the immune system; important in the formation of RBC and helps body use Vit K
Summarise the epidemiology of vitamin E deficiency
very rare
what are the presenting symptoms of vitamin E deficiency?
Weakness
Loss of vibration sense
Decline in visual field
Numbness and tingling
what are the signs of vitamin E deficiency?
Hyporeflexia
Decreaed proprioception
Distal muscle weakness
Limited upward gaze
Loss of vibration sense
Ataxia
Dysarthria
Retinopathy
Compromise immune system
What are the appropriate investigations for vitamin E deficiency an interpret the results?
Serum alpha-tocopherol level
Generate a management plan for vitamin E deficiency
Supplements (around 1000 IU/day)
Food sources of Vitamin E: veg oils, nuts, seeds, spinach/broccoli, fortified foods like cereals and fruit juices
what are the complications of vitamin E deficiency?
Complete blindness
Cardiac arrhythmia
Dementia
describe the pathophysiology of vitamin K deficiency?
Vitamin K is important for coagulopathy (co-factor for synthesis of clotting factors II, VII, IX and X) so main symptom is excessive bleeding; imp for bone health
what are the risk factors for vitamin K deficiency?
Anticoagulants
Lack of vitamin K in diet
Liver disease – decreased synthesis of vitamin-K dependent factors
Antibiotics which interfere with vit K absorption
Fat malabsorption e.g. in coeliac disease, CF, IBD, short bowel syndrome, biliary tract disease
Infants at risk of breast milk low in vit K
recognise the presenting symptoms of vitamin K deficiency?
Easily bruising
Dark black, tar like stool
Nose bleeds
Epistaxis
Bleeding gums
what are the signs of vitamin K deficiency?
bruising
what are the appopriate investigations for vitamin K deficiency and interpret the results?
History
Prothrombin time
Plasma level of Vit K can be measured
generate a management plan for vitamin K deficiency?
In life-threatening bleeds, administer FFP before vitK
Vitamin K supplement – available as phytomenadione or synthetic water-soluble analogue menadiol sodium diphosphate
Diet rich in vitK: green leafy vegs, green peas and beans, spinach, broccoli, whole wheat and oats
identify the possible complications of vitamin K deficiency?
Excessive bleeding and anaemia
summarise the prognosis of patients with vitamin K deficiency
Good if treated early
