vitamin deficiency - A D C

Question 1

Vit A deficiency syndrome

Answer 1

xerophthalmia

Question 2

what is B1 (thiamine) deficiency syndrome

Answer 2

BeriBeri,

Wernicke’s encephalopathy

Question 3

what is B2 (riboflavin) deficiency syndrome

Answer 3

angular stomatitis,

cheilitis

Question 4

what is B6 (pyridoxine) deficiency syndrome

Answer 4

polyneuropathy

Question 5

what is vit C deficiency syndrome

Answer 5

scurvy

Question 6

what is vitamin D deficiency syndrome

Answer 6

rickets

osteomalacia

Question 7

what is vitamin E deficiency syndrome

Answer 7

haemolysis,

neurological deficit

Question 8

aetiology of deficiency of fat sol vitamins (A D E K)

Answer 8

malnutrition

malabsorption syndromes with steatorrhea (CF, coeliac)

bile acid def (eg cholestasis, bile acid malabsorption)

medications or supplements (orlistat, mineral oil)

genetic disorders - hereditory forms of rickets

Question 9

aetiology of deficiency of water soluble vitamins - B C

Answer 9

restricted diet - vegan

malabsorption disorder - gastritis, gastric resection

congenital disorders - hartnup disease

Question 10

RF for scurvy

Answer 10

poor

pregnant

odd diet

Question 11

definition of xerophthalmia

Answer 11

dry eyes secondary to deficient tear production

Question 12

complication of xerophthalmia

Answer 12

if left untreated - progess to keratomalacia

-> here cornea softens, thins and eventually ulcerates

blindness

immunosuppression - increase risk of measles

poor growth

dry age related macular degeneration

Question 13

epidemiology of xerophthlamia

Answer 13

peak incidence 2-5yrs

40million children affected worldwide

big cause of blindness in tropics

Question 14

sx of xerophthalmia

Answer 14

conjunctivae become dry

Question 15

signs of xerophthalmia

Answer 15

night blindness (nyctalopia)

tunnel vision

poor acutity

dry conjunctivae (xerosis)

cornea is unwettable and loses transparency

small oval/triangular foamy plaques occur, raised from interpalpebral conjunctiva - Bitot spot

xerosis cutis - dry skin

retinopathy

Question 16

Ix for xerophthalmia

Answer 16

visual fields

dark adapted electroretinography

low plasma vit A

Question 17

Mx of xerophthalmia

Answer 17

vit A replacement

address cause - alcoholism, nutrition, poverty

improve diet - liver, kidney, butter, egg yolks, leafy veg

Question 18

Px of xerophthalmia

Answer 18

vit a reverses the changes

Question 19

aetiology of vitamin A deficiency

Answer 19

disorders associated with fat malabsorption - IBD, coeliac, CF, pancreatic insufficiency, cholestasis

malnutrition - most common cause in developing countries

Question 20

aetiology of vitamin D deficiency

Answer 20

lack of sun

malnutrition - chronic alcohol abuse

malabsorption disorders - fat malasorption, chronic GI disease

CKD or advanced liver disease = impaired hydroxylation of precursers

breastfeeding withourt supplements

preterm infants at increased risk

CP450 induces eg anticonvulsants increase the metabolism of vit D

Question 21

clinical features of vit D deficiency

Answer 21

oesteomalacia

rickets

sx of hypocalcaemia

Question 22

sx and signs of hypocalcaemia

Answer 22

SPASMODIC

• spasms - carpopedal spasms = trousseau’s sign
• perioral paraesthesia
• anxious, irritable, irrational
• seizures
• muscle tone increased in smooth muscle = colic, wheeze, dysphagia
• orientation impaired (time, place, person) and confusion
• dermatitis - atopic, exfoliative
• impetigo herpetiformis
• Chvostek’s sin, choreoathetosis, cataract, cardiomyopathy (long QT)

Question 23

features of mild hypocalcaemia

Answer 23

cramps

perioral numbness/parasthesiae

Question 24

features of severe hypocalcaemia

Answer 24

carpopedal spasm (esp if brachial artery compressed - Trousseau’s sign)

laryngospasm

seizures

neuromuscular excitability demonstrated by tapping over parotid (facial nerve) = facial muscles twitch - Chvostek’s sign

cataracts if chronic

Question 25

Mx of hypocalcaemia

Answer 25

mild - give Ca with daily plasma levels in CKD - may need alfacalcidiol severe - calcium gluconate IV over 30mins, if due to resp alkalosis - correct

Question 26

complications of vitamin D deficiency

Answer 26

hypophosphtaemia hyperparathyroidism osteoporosis treatment related vit D toxicity increased risk of: * low BMD and fractures in HIV * cancer - prostate, colon, breast, ovarian, pancreatic * autoimmune disease * T2DM * heart disease * HTN * neurocognitive dysfunction * infectious disease * OA * depression * schizophrenia

Question 27

definition of vitamin D deficiency

Answer 27

serum 25-hydroxyvitamin D level of \<50nanomoles/L

Question 28

epidemiology of vitamin D deficiency

Answer 28

most common nutritional deficiency worldwide in US and Europe 40% \>50yrs are deficient

Question 29

RF for vitamin D deficiency

Answer 29

people of colour obesity malabsorption history of liver failure of CKD \>50yrs history of tumour steroids, anti-epileptics, highly active antiretroviral therapy, rifampicin, St John's wort neonates children who avoid outside inadequate diet and supplements malabsorption mutations granulomatous disease eg sarcoid/rickets - increased vit d destruction primary hyperparathyroidism - increased destruction hyperthyroidism - enhances the metabolism of 25-hydroxyvitamin D = reduced levels

Question 30

clinical features of vit D deficiency

Answer 30

bowed legs widening of ends of long bones - rickets (hypertrophy of the epiphuseal plates = widening fo wrists) delayed tooth eruption and early dental caries - rickets chest deformity - in rickets, muscle traction on softened ribcage -\> pectus carinatum, thoracic asymmetry, widening of thoracic base throbing, aching bone discomfort and/or irritability - osteomalacia head sweating - in children, from increased neuromuscular activity localised/generalised bone tenderness prox muscle weakness rachitic rosary frontal bossing - rickets, increased bone formation and flattening of forehead waddling gait - due to pain in hips

Question 31

Ix for vitamin D deficiency

Answer 31

serum 25-hydroxyvitamin D - \<50nanomoles/L (52-72 is insufficiency) serum ALP - high in rickets/osteomalacia due to high bone turnover rate serum Ca - normal due to secondary hyperparathyroidism fasting serum phosphate - low normal/low - secondary hyperparathyroidism = phosphturia plain-film XR of knees and wrists - cupping splaying and fraying of metaphysis, and looser's zones (pseudofracture)

Question 32

principle of Mx of vitamin D deficiency

Answer 32

should have serum 25-hydroxyvitamin D \>75nanomoles/L correction promotes growth and deposition of calcium into the skeleton children with skeletal manifestations should be treated aggressively - earlier intervention = better prognosis with resolution of deformity correction in adults improves BMD and stimulates mineralisation of the collagen matrix = resolution of pain

Question 33

Mx of vitamin D deficiency

Answer 33

vitamin D2 (ergocalciferol) or Vit D3 (cholecalciferol) - oral for 6-8wks then lower maintenance dose continued high dose needed if intestinal or fat malabsorption syndromes, taking glucocorticoids, st john's wort, rifampcin highly active antiretroviral therapy need Ca supplement if unable to metabolise 25 hydroxyvit D to 1,25 dihydroxyvit D, or no recognition of 1,25 - give vut d and 1,25 (calcitriol) or one of the active analogues (paracalcitol or doxercalciferol) in CKD - high phosphate - need phosphate binder eg calcium carbonate. if GFR \<50% might need calcitrion/active metabolite

Question 34

prognosis of Vit D deficiency

Answer 34

most asymptomatic if symptomatic children * earlier intervention better * in 1 week - biochem changes (raise in phosphorus and ca) and XR changes * physical exam normal in 6mo in adults * improve BMD after 1-2yrs * stimulate mineralisation of matrix = resolution of bone pain from osteomalacia * improvement in secondary hyperparathyroidism, muscle strength, osteomalacioc bone pain - in 3-6mo

Question 35

definition of vit C deficiency

Answer 35

scurvy is a life threatening disorder due to Vit C deficiency

Question 36

RF for vit C deficiency

Answer 36

refugees victims of famine older people alcohol misuse atypical diet children with autism or idiosyncratic behavioural abnormalities infants only drinking cow's milk end stage renal disease and/or haemodialysis dependance smoking surgery sepsis HIV critical illmess ARDS pancreatitis

Question 37

signs and sx of vit C deficiency

Answer 37

constitutional sx endothelial dysfunction and haemorrhage sx: * easy bruising/bleeding * myalgia * arthralgia * joint swelling * petechial and perifollicular haemorrhages - legs and feet * oral mucosal petechiae * coiled hairs * follicular hyperkeratosis * bleeding from gums, nose, hair follicles, or into joints, bladder and gut gait impairment/leg pain - impaired bone growth - frog like leg position with little leg movement pedal oedema - from cardiac failure or local endothelial dysfunction poor wound healing tooth loss - haemorrhaging gingivitis affecting intradental papillae gingival discolouration gum swelling lid petechiae and haemorrhage proptosis - from retrobulbar, periorbital, or orbital subperiosteal haemorrhage conjunctival and subconjunctival haemorrhage foul breath - halitosis oedema

Question 38

Ix for vitamin C deficiency

Answer 38

FBC and peripheral smear - normocytic anaemia, micro or megaloblastic if other deficiencies are presnt serum ascorbic acid - identify amount and severity of deficiency, and exclude haematological disorders - deficient level \<11.4micromol/L leukocyte ascorbic acid - deficient level \<57nanomol/10(8) cells whole blood ascorbic acid - deficient level \<17micromol/L XR of knee and wrist - corner fraction sign, ground glass appearance, trabecular atrophy, Pelkan's sign, Frankel's sign * Pelkan's - irregularities, fragmentation and spurs at the metaphyseal margins * Frankel's - lucent line immediately beneath a white line at margin of growth plate

Question 39

Mx of vitamin C deficiency

Answer 39

diet change ascorbate supplements - oral 300-500mg/day parenteral if severe disease, poor enteric function or swallowing or multiple deficiencies start as soon as possible after 2 weeks follow general approach to prevention - can be as little as 6.5mg/day chronic supplementation might be indicated in some

Question 40

prognosis of vitamin C deficiency

Answer 40

after treatment signs and sx improve rapidly - once body stores achieve a level sufficient to meet demands if not treated rapidly risk of death is high long term - full recovery, provided no major haemorrhagic complications occur eg stroke

Question 41

complications of vitamin C deficiency

Answer 41

intracerebral haemorrhage endocardial haemorrhage neck and back pain

Question 42

aetiology of vitamin C deficiency

Answer 42

always due to lack of dietry intake

Question 43

pathophysiology of vit C deficiency

Answer 43

it is in fruits, veg, organ meats, certain animal milks absorbed from gut by active and passive transport Vit c is essential for collagen synthesis = blood vessel lose their integrity = perivascular oedema, erythrocyte extravasion and haemorrhage Vit C also increases iron absorption - so get iron deficiency plays a role in noradrenaline synthesis, amidation of peptide hormones and tyrosine metabolism modifies host disease - malignancy, atherosclerosis, dementia

Question 44

epidemiology of vitamin C deficiency

Answer 44

endemics rare

Question 45

gingivitis

Answer 45

gum inflammation+- hypertrophy

Question 46

constitutional sx of vit C deficiency

Answer 46

arthralgia myalgia weakness lethargy nausea emesis weight loss dry skin depression dyspnoea listlessness anorexia cachexia