vitamin deficiency - A D C Flashcards
Vit A deficiency syndrome
xerophthalmia
what is B1 (thiamine) deficiency syndrome
BeriBeri,
Wernicke’s encephalopathy
what is B2 (riboflavin) deficiency syndrome
angular stomatitis,
cheilitis
what is B6 (pyridoxine) deficiency syndrome
polyneuropathy
what is vit C deficiency syndrome
scurvy
what is vitamin D deficiency syndrome
rickets
osteomalacia
what is vitamin E deficiency syndrome
haemolysis,
neurological deficit
aetiology of deficiency of fat sol vitamins (A D E K)
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
aetiology of deficiency of water soluble vitamins - B C
restricted diet - vegan
malabsorption disorder - gastritis, gastric resection
congenital disorders - hartnup disease
RF for scurvy
poor
pregnant
odd diet
definition of xerophthalmia
dry eyes secondary to deficient tear production
complication of xerophthalmia
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
epidemiology of xerophthlamia
peak incidence 2-5yrs
40million children affected worldwide
big cause of blindness in tropics
sx of xerophthalmia
conjunctivae become dry
signs of xerophthalmia
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
Ix for xerophthalmia
visual fields
dark adapted electroretinography
low plasma vit A
Mx of xerophthalmia
vit A replacement
address cause - alcoholism, nutrition, poverty
improve diet - liver, kidney, butter, egg yolks, leafy veg
Px of xerophthalmia
vit a reverses the changes
aetiology of vitamin A deficiency
disorders associated with fat malabsorption - IBD, coeliac, CF, pancreatic insufficiency, cholestasis
malnutrition - most common cause in developing countries
aetiology of vitamin D deficiency
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
clinical features of vit D deficiency
oesteomalacia
rickets
sx of hypocalcaemia
sx and signs of hypocalcaemia
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)
features of mild hypocalcaemia
cramps
perioral numbness/parasthesiae
features of severe hypocalcaemia
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
Mx of hypocalcaemia
mild - give Ca with daily plasma levels
in CKD - may need alfacalcidiol
severe - calcium gluconate IV over 30mins, if due to resp alkalosis - correct
complications of vitamin D deficiency
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
definition of vitamin D deficiency
serum 25-hydroxyvitamin D level of <50nanomoles/L
epidemiology of vitamin D deficiency
most common nutritional deficiency worldwide
in US and Europe 40% >50yrs are deficient
RF for vitamin D deficiency
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
clinical features of vit D deficiency
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
Ix for vitamin D deficiency
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)
principle of Mx of vitamin D deficiency
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
Mx of vitamin D deficiency
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
prognosis of Vit D deficiency
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
definition of vit C deficiency
scurvy is a life threatening disorder due to Vit C deficiency
RF for vit C deficiency
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
signs and sx of vit C deficiency
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
Ix for vitamin C deficiency
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
Mx of vitamin C deficiency
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
prognosis of vitamin C deficiency
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
complications of vitamin C deficiency
intracerebral haemorrhage
endocardial haemorrhage
neck and back pain
aetiology of vitamin C deficiency
always due to lack of dietry intake
pathophysiology of vit C deficiency
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
epidemiology of vitamin C deficiency
endemics
rare
gingivitis
gum inflammation+- hypertrophy
constitutional sx of vit C deficiency
arthralgia
myalgia
weakness
lethargy
nausea
emesis
weight loss
dry skin
depression
dyspnoea
listlessness
anorexia
cachexia
