Vitamins and Minerals Flashcards
IRON
Absorption:
- Takes place in upper small intestine
- About 10% of dietary iron absorbed
- Fe2+ (ferrous iron) much better absorbed than Fe3+ (ferric iron)
- Absorption is regulated according to body’s need
- Absorption is increased by vitamin C, gastric acid
- Absorption is decreased by proton pump inhibitors, tetracycline, gastric achlorhydria and tannin (found in tea)
Distribution in body:
- total body iron = 4g
- haemoglobin = 70%
- ferritin and haemosiderin = 25%
- myoglobin = 4%
- plasma iron = 0.1%
Transport:
Carried in plasma as Fe3+ bound to transferrin
Storage:
Stored in tissues as FERRITIN
Excretion:
Lost via intestinal tract following DESQUAMATION
Pellagra
Pellagra is a rare condition in the United Kingdom but it is seen in patients with carcinoid syndrome. It is caused by a deficiency in vitamin B3, (Niacin) and classically presents as the ‘4 Ds’ dermatitis, dementia, diarrhoea and death. Niacin can be absorbed through the diet or converted in vivo from tryptophan. Patients with carcinoid syndrome are at increased risk as tryptophan stores are metabolised to serotonin.
Pellagra is a caused by nicotinic acid (niacin) deficiency. The classical features are the 3 D’s - dermatitis, diarrhoea and dementia, also Depression
Pellagra may occur as a consequence of isoniazid therapy (isoniazid inhibits the conversion of tryptophan to niacin) and it is more common in alcoholics.
Features dermatitis (brown scaly rash on sun-exposed sites - termed Casal's necklace if around neck) diarrhoea dementia, depression death if not treated
Pellagra occurs primarily in countries such as India and China, in which corn is a staple food. In the UK it is uncommon, and largely seen in patients with alcohol dependency or anorexia nervosa. Niacin is absorbed from foods such as beans and eggs and is also converted from amino acid tryptophan. Pellagra may manifest in carcinoid syndrome, in which tryptophan is converted to serotonin.
Beri-Beri
Beriberi is caused by thiamine deficiency and typically causes:
- a peripheral neuropathy
- high-output cardiac failure
- associated with weight loss.
Pellagra - Example Question
A 58 year-old man is referred to the clinic with chronic diarrhoea and episodes of facial flushing. A computed tomography scan of her chest and abdomen reveal she has a neuroendocrine carcinoma of the appendix, causing carcinoid syndrome.
She refuses treatment and presents six months later having been referred by a neurologist as having early onset dementia and a rapidly evolving photosensitive rash on her trunk and upper arms.
Which of the following is the most likely diagnosis?
Systemic lupus erythematosus Herpes Zoster infection > Pellagra Wernicke-Korsakoff syndrome Porphyria
The most likely diagnosis in this case is pellagra, a vitamin deficiency disease most frequently caused by a chronic lack of niacin (vitamin B3). In carcinoid syndrome, neuroendocrine tumours along the GI tract use tryptophan as the source for serotonin production, which limits the available tryptophan for niacin synthesis, thus carcinoid syndrome produces a niacin deficiency.
Vitamin C
= water soluble vitamin
Functions:
- antioxidant
- collagen synthesis - acts as a cofactor for enzymes that are required for the hydroxylation of proline and lysine in the synthesis of collagen
- facilitates iron absorption
- cofactor for norepinephrine synthesis
Scurvy
Vitamin C deficiency = SCURVY
Leads to defective collagen synthesis > capillary fragility (tendency to bleed) and poor wound healing
Features:
- gingivitis
- loss of teeth
- epistaxis
- poor wound healing
- bleeding from gums
- haematuria
- general malaise
Vitamin D Resistant Rickets
= X-linked dominant condition
Usually presents in infancy with FAILURE TO THRIVE
Caused by impaired phosphate reabsorption in renal tubules
Features:
- N serum calcium
- Low phosphate
- Elevated ALP
- X-ray changes: cupped metaphyses with widening of epiphyses
Diagnosis:
- Demonstrated by increasing urinary phosphate
Mx:
- High dose Vit D supplements
- Oral phosphate supplements
Vitamin C and Scurvy
Vitamin C deficiency (scurvy)
Vitamin C is found in citrus fruits, tomatoes, potatoes, Brussel sprouts, cauliflower, broccoli, cabbage and spinach. Deficiency leads to impaired collagen synthesis and disordered connective tissue. It is associated with severe malnutrition as well as drug and alcohol abuse, and those living in poverty with limited access to fruits and vegetables.
Symptoms and signs include:
Follicular hyperkeratosis and perifollicular haemorrhage
Ecchymosis (a discoloration of the skin resulting from bleeding underneath)
Gingivitis with bleeding and receding gums
Sjogren’s syndrome
Arthralgia
Oedema
Impaired wound healing
Generalised symptoms such as weakness, malaise, anorexia and depression
Scurvy Diagnosis - Example Question
A 42-year-old man presents to the emergency department due to bleeding from hair follicles on his head. He has also noticed that he has been off his food and losing weight. He is currently homeless after having been made redundant from his job one year ago. He is alcohol dependent with 30-units per week of hard liquor. He is not confused.
He has a past medical history of tuberculosis, for which he completed treatment six months. This treatment finished two months ago. On examination, he appears unkempt with poor oral hygiene and gingivitis. He has global muscle weakness rated at 4+/5 on the MRC scale. There is no sensory impairment. What is the most likely diagnosis?
Pellagra > Scurvy Beriberi Wernicke-Korsakoff syndrome Recurrence of tuberculosis
The correct answer is scurvy. He is a homeless and alcohol-dependent patient who is very likely to have a very poor diet. The combination of bleeding hair follicles and gingivitis is highly suggestive of vitamin C (ascorbic acid) deficiency. Pellagra is associated with diarrhoea and dementia. Beriberi can be associated with peripheral neuropathy with sensory involvement, or heart failure and oedema. Neither of these cases is described here. The classical triad of nystagmus, ophthalmoplegia and ataxia with confusion is not described, making Wernicke-Korsakoff syndrome less likely. The absence of a cough, haemoptysis and night sweats makes TB recurrence less likely.
Vitamin B1 - Thiamine
Vitamin B1 (thiamine)
Thiamine is a water soluble vitamin of the B complex group. One of it’s phosphate derivates, thiamine pyrophosphate (TPP), is a coenzyme in the following enzymatic reactions:
pyruvate dehydrogenase complex
pyruvate decarboxylase in ethanol fermentation
alpha-ketoglutarate dehydrogenase complex
branched-chain amino acid dehydrogenase complex
2-hydroxyphytanoyl-CoA lyase
transketolase
Thiamine is therefore important in the catabolism of sugars and aminoacids. The clinical consequences of thiamine deficiency are therefore seen first in highly aerobic tissues such as the brain (Wenicke-Korsakoff syndrome) and the heart (wet beriberi).
Causes of thiamine deficiency:
alcohol excess
malnutrition
Conditions associated with thiamine deficiency:
Wernicke’s encephalopathy: nystagmus, ophthalmoplegia and ataxia
Korsakoff’s syndrome: amnesia, confabulation
dry beriberi: peripheral neuropathy
wet beriberi: dilated cardiomyopathy
Vitamin B1 - Thiamine Deficiency: Example Question
A 58-year-old man with long-standing Crohn’s disease presents with a 1-year history of fatigue. In the last month, he has developed weakness and muscle pain. He also reports a number of trips and falls.
On examination, he is thin and pale. Heart rate is 85 beats per minute and blood pressure is 130/80 mmHg. His chest is clear and heart sounds normal, with no added sounds. His abdomen is soft and has a laparotomy scar. Neurological examination reveals bilateral foot drop, with reduced ankle jerks. He has widespread muscle wasting and calf fasciculations. He has reduced pin-prick sensation to mid shin.
Blood tests show:
Hb 144 g/l
Platelets 195 * 109/l
WBC 6.3* 109/l
Na+ 137 mmol/l K+ 4.5 mmol/l Urea 7 mmol/l Creatinine 91 µmol/l Corrected calcium 2.5 mmol/l HbA1c 45 mmol/mol
What is the diagnosis?
Diabetes mellitus Motor neurone disease > Beriberi Pellagra Friedreich's ataxia
This patient is malnourished due to Crohn’s disease. Chronic thiamine deficiency has led to his fatigue and neurological symptoms. Beriberi typically presents with fatigue, nausea and abdominal pain. If left untreated it can progress, leading to peripheral neuropathy, muscle pain and congestive cardiac failure. Diagnosis is usually made after a response to parenteral thiamine and symptoms tend to improve rapidly with treatment.
Diabetes mellitus and pellagra can cause a peripheral neuropathy, however, this man has a normal HbA1c. Pellagra presents with confusion, rash and diarrhoea. The sensory findings rule out motor neurone disease. Friedrich’s ataxia is an autosomal recessive disorder that typically presents in much younger patients.
Alcohol dependency, renal dialysis and a diet high in milled rice are also risk factors for Beriberi.
Vitamin D Deficiency and Mx
Vitamin D deficiency versus insufficiency
Description > Serum levels > Treatment
Adequate vitamin D
>50 nmol/L
Dietary recommendations
Insufficient vitamin D
30-50 nmol/L
maintenance dose vitamin D
Deficient vitamin D
<30 nmol/L
loading dose vitamin D
Example Question:
A 26-year-old man is reviewed in gastroenterology clinic. He is known to have Crohn’s disease which has been stable over the last six months and not required any recent steroids or hospital admissions. Routine blood tests demonstrate a vitamin D level at 22 nmol/L. All other blood tests, including calcium, are within normal range. What is the most appropriate management plan?
No treatment needed Dietary advise only Maintenance dose vitamin D > Loading dose vitamin D Combined calcium and vitamin D
The correct answer is loading dose vitamin D. He has a serum concentration <30 nmol/L and therefore has vitamin D deficiency, likely secondary to his Crohn’s disease. He, therefore, needs a loading dose of vitamin D. As calcium levels are normal there is no current indication for supplementation.
Osteomalacia
Osteomalacia
Basics
normal bony tissue but decreased mineral content
rickets if when growing
osteomalacia if after epiphysis fusion
Types vitamin D deficiency e.g. malabsorption, lack of sunlight, diet renal failure drug induced e.g. anticonvulsants vitamin D resistant; inherited liver disease, e.g. cirrhosis
Features
rickets: knock-knee, bow leg, features of hypocalcaemia
osteomalacia: bone pain, fractures, muscle tenderness, proximal myopathy
Investigation
low calcium, phosphate, 25(OH) vitamin D
raised alkaline phosphatase
x-ray: children - cupped, ragged metaphyseal surfaces; adults - translucent bands (Looser’s zones or pseudofractures)
Treatment
calcium with vitamin D tablets
Pellagra - Example Question
A 45-year-old woman is admitted with hallucinations. She has a long history of alcohol dependency and is being treated by her GP for hypothyroidism. Further questioning of her husband reveals a 3-month history of diarrhoea, difficulty swallowing and an itchy rash on her arms. Prior to this she had been irritable and suffered from regular bouts of vomiting.
The examination is limited as the patient is aggressive . There is a pigmented, scaly rash on her arms and neck. Heart sounds are normal, her chest is clear and her abdomen soft. Neurological examination reveals generalised weakness.
Blood tests show:
Hb 142 g/l
Platelets 200 * 109/l
WBC 5.3 * 109/l
Na+ 140 mmol/l
K+ 4.2 mmol/l
Urea 6 mmol/l
Creatinine 84 µmol/l
TSH 4.0 U/mL
Free T3 3.1 pg/mL
Free T4 1.5 ng/L
What is the most likely diagnosis?
Beriberi Thyroxine toxicity Systemic lupus erythematosus (SLE) > Pellagra Darier's disease
This lady has pellagra, caused by niacin (vitamin B3) deficiency. It occurs primarily in countries such as India and China, in which corn is a staple food. In the UK it is uncommon, and largely seen in patients with alcohol dependency or anorexia nervosa. Niacin is absorbed from foods such as beans and eggs and is also converted from amino acid tryptophan. Pellagra may manifest in carcinoid syndrome, in which tryptophan is converted to serotonin.
Over-treatment or deliberate overdose of thyroxine could cause some of this patient’s symptoms, but her thyroid function tests are normal. SLE and Darier’s disease both cause a light-sensitive rash, but would not cause the gastrointestinal symptoms. Cognitive disturbance may be seen in SLE.
Pellagra is distinguished from beriberi by the presence of a rash and gastrointestinal symptoms. Like beriberi, it can lead to confusion and memory deficits. Alcoholic patients may, of course, present with both. Other signs include dilated cardiomyopathy, oesophagitis and ataxia.
Osteomalacia - Example Question
A 28-year-old woman presents to the gastroenterology clinic for review. She has been diagnosed with coeliac disease some 2 years earlier, and has been suffering from severe tiredness, muscle aches and proximal weakness for the past few months. On examination her blood pressure is 112/70 mmHg, pulse is 75 beats per minute and regular. You confirm proximal muscle weakness.
Investigations
Ca++ 2.0 mmol/l
Alkaline phosphatase 275 IU/l
Which of the following is the most useful next investigation?
CK Parathyroid hormone > Vitamin D Muscle biopsy Electromyography
Coeliac disease is known to interfere with absorption of fat soluble vitamins, including vitamin D, and the low calcium and elevated alkaline phosphatase, coupled with symptoms of proximal myopathy fits with a diagnosis of osteomalacia. Vitamin D levels are therefore the next investigation of choice.
CK and muscle biopsy are indicated for possible inflammatory myositis, and the limited proximal weakness seen here, coupled with low calcium is much more consistent with osteomalacia. Parathyroid hormone may be elevated, but this is secondary to low vitamin D and calcium. Electromyography is most useful for assessment of motor neuropathy, which doesn’t fit with the painful proximal muscle weakness seen here.
Vitamin D Deficiency - Example Question
A 34-year-old woman is reviewed in clinic. She has been suffering from increasing tiredness for the last three months. She has no other symptoms and specifically denies pain, bleeding, weight loss and mood problems. She has a past medical history of asthma but has not needed her blue inhaler in over a year. She has no allergies. Her only regular medication is the oral contraceptive pill. Blood tests show a normal FBC, U&Es, calcium, parathyroid hormone but low vitamin D (32 nmol/L). What is the most appropriate treatment in regards to her low vitamin D?
Dietary advise only Loading dose vitamin D > Maintenance dose vitamin D Combined calcium and vitamin D No treatment needed
This patient has vitamin D insufficiency which may explain her tiredness. This should be managed with maintenance dose vitamin D. Loading dose would be appropriate if her serum level was less than 30 nmol/L. Dietary advice would be appropriate for patients with adequate levels, above 50 nmol/L. As calcium is normal and there is no evidence of low calcium diet there is no need for calcium supplementation.
Vitamin D deficiency versus insufficiency
Description Serum levels Treatment
Adequate vitamin D >50 nmol/L dietary recommendations
Insufficient vitamin D 30-50 nmol/L maintenance dose vitamin D
Deficient vitamin D <30 nmol/L loading dose vitamin D
Source:
‘Vitamin D Deficiency in Adults - Treatment and Prevention.’ Clinical Knowledge Summaries. National Institute for Health and Care Excellence, Nov. 2016.
Phenytoin and Vitamin D - Example Question
A 52-year-old lady was seen in the general medicine clinic with aches and pains. The pains were present in her arms and legs, and not associated with her joints. They have been present for several months, and she was unable to identify any precipitating factors. She also felt that on occasion she felt generally weak and tired, though denied the presence of any specific weakness. Her past medical history comprised of epilepsy which was well controlled with phenytoin 500mg BD for several years, as well as hypertension and asthma. In addition to phenytoin 500mg BD she was prescribed ramipril 5mg OD, Clenil modulite 200mcg BD, salmeterol 100mcg BD and Elleste duo for the last six months. Upon specific questioning, she stated that she ate a nutritionally balanced diet, and that she had not suffered a previous fracture. Her mother was diagnosed with osteoporosis when she was 64-years-old, and she did not smoke. She drank 10 units of alcohol per week.
On examination, she was systemically well, with a blood pressure of 132/68 mmHg, heart rate 84, respiratory rate 16/min and body mass index of 23. Examination of her cardiovascular system revealed the presence of normal heart sounds and was unremarkable. Examination of the respiratory and gastrointestinal systems was likewise unremarkable except for the presence of gingival hypertrophy. Examination of the musculoskeletal system revealed the presence of Heberden’s nodes but was also otherwise unremarkable with a full range of movement in all joints. Examination of the neurological system was normal with a power of 5/5 in all muscle groups and normal sensation, tone and coordination. Cranial nerve and fundoscopy examinations were unremarkable. Examination of the thyroid gland was unremarkable.
Investigations revealed the following results:
Bilirubin 22 µmol/l ALP 262 u/l ALT 23 u/l Albumin 42 g/l Protein 76 g/l Globulin 34 g/l Adjusted calcium 2.06 mmol/l Phosphate 0.78 mmol/l Vitamin D level pending result Parathyroid hormone 88 (NR 11-54 pg/ml) IgG 11.2 g/L (NR 7.0 18.0) IgA 3.2 g/L(NR 0.8 4.0) IgM 2.1 g/L (NR 0.4 2.5)
Urinary Bence Jones Protein: negative
What is the most likely underlying diagnosis?
Fibromyalgia Paget's disease Primary hyperparathyroidism Osteoporosis > Osteomalacia
Phenytoin is known to affect the metabolism of vitamin D, and over prolonged periods of time may result in osteomalacia. This patient is also likely suffering other sequelae of prolonged phenytoin use as manifested by the presence of gingival hypertrophy. She has a raised parathyroid hormone level secondary to the low vitamin D level, and there is no evidence of osteoporosis.
Thiamine Deficiency and Hyperemisis Gravidarum: Example Question
A 26-year-old primigravida lady is brought to the hospital at 17 weeks gestation with worsening confusion. Her husband states that she has been vomiting profusely for the past 3 weeks. She has been unable to eat but she has managed to keep down small amounts of fluid.
Her past medication history is unremarkable and she takes no regular medications.
On examination, she is afebrile. Her pulse is 108bpm and her blood pressure is 103/68mmHg. She is alert but disorientated to time and place. Cranial nerve examination is remarkable for bilateral VIth nerve palsy and multi-directional nystagmus. Peripheral neurological examination reveals MRC grade 4/5 power in both lower limbs. Her lower limb jerks are absent and there is bilateral loss of distal vibration sense. Her plantar responses are downgoing.
A set of blood tests are requested:
Hb 117 g/l Na+ 132 mmol/l Platelets 362 * 109/l K+ 2.8 mmol/l WBC 12.3 * 109/l Urea 8.9 mmol/l Neuts 10.1 * 109/l Creatinine 112 µmol/l Lymphs 1.9 * 109/l CRP 17 mg/l Eosin 0.01 * 109/l Glucose 3.1 mmol/l
What is the most appropriate treatment?
Folic acid Niacin Vitamin B12 Intravenous dextrose > Thiamine
The patient has presented with symptoms and signs consistent with Wernicke’s encephalopathy (confusion, nystagmus) and dry beriberi (peripheral neuropathy). There is a clinical association between Hyperemesis gravidarum and thiamine deficiency, particularly when it is prolonged and normal dietary intake is compromised. This patient should receive high-dose parenteral thiamine without delay.
Intravenous dextrose administered before correction of thiamine deficiency may exacerbate her condition and should be avoided.
Subacute combined degeneration of the cord would be one of the major differentials in this case. However, the downgoing plantar responses and presence of ocular signs make this less likely.
Niacin is used to treat pellagra. This patient is confused, but there is no mention of diarrhoea or a skin rash in the vignette.
Vitamin D Supplementation Following Testing
Serum 250HD < 30nmol/L - Treatment recommended
Serum 250HD 30-50nmol/L - Treatment advised in patients with:
- fragility fractures
- osteoporosis
- Sx suggestive of Vit D Deficiency
- Reduced exposure to sunlight
- Raised PTH
- Conditions assoc w malabsorption
Serum 250HD > 50nmol/L: Provide reassurance and give advice on maintaining adequate vit D levels though safe sunlight exposure and diet
Reference - National Osteoporosis Society 2013, Vit D and Bone Health
Testing for Vitamin D Deficiency
The key message here is that not many people warrant a vitamin D test!
The NOS guidelines specify that testing may be appropriate in the following situations:
- patients with bone diseases that may be improved with Vit D treatment e.g. known osteomalacia or Paget’s
- patients with bone diseases prior to specific treatment where correcting the bit deficiency is appropriate e.g. prior to IV Zolendronate or Denosumab
- patients with musculoskeletal Sx that could be attributed to Vit D deficiency e.g. bone pain ?osteomalacia
NB Patients with osteoporosis should ALWAYS be given calcium/vit D supplements so testing is not considered necessary
People who are at higher risk of vit D deficiency should be treated anyway so again, testing is not necessary
Vitamin D Supplementation
Vit D Supplementation has been a hot topic for a number of years now. The muddied waters are slightly clearer following release of the following:
- 2012: letter by chief medical officer regarding vit D supplementation
- 2013: national osteoporosis society (NOS) release on UK Vit D Guideline
The following groups should be advised to take Vit D supplementation:
- all pregnant and breastfeeding women should take a daily supplement containing 10 micrograms of vit D
- all children aged 6m-5years - babies do not need to take a supplement if they are taking more than 500mL formula milk/
Zinc Deficiency
- Perioral Dermatitis (red-crusted lesions around mouth and lips)
- Acrodermatitis
- Alopecia
- Short stature
- Hypogonadism
- Hepatosplenomegaly
- Cognitive Impairment
- Geophagia (ingesting clay/soil)
Vitamin B12 Deficiency
Vit B12 is mainly used in body for RBC development and also maintenance of nervous system
Binds to INTRINSIC FACTOR (secreted from parietal cells in the stomach) and is actively absorbed in terminal ileum. A small amount of Vit B12 is passively absorbed without being bound to intrinsic factor
Causes of Vit B12 Deficiency:
- Pernicious anaemia
- Post-gastrectomy
- Poor diet (alcoholic)
- Disorders of terminal ileum - Crohns
- Metformin (rare)
Features of Vit B12 Deficiency
- Macrocytic anaemia
- Sore tongue and mouth
- Neurological Sx eg Ataxia
- Neuropsychiatric Sx eg mood disturbances
- Subacute Combined Degeneration of the Cord (SCDC)
Mx:
- If no neuro involvement 1mg of IM Hydroxycobalamin 3 x a week for 2 weeks, then once every 3 months
NB: if patient is also deficient in folic acid, important to treat B12 deficiency FIRST to avoid precipitating subacute combined degeneration of the cord
PELLAGRA - 4Ds
DERMATITIS
DIARRHOEA
DEMENTIA
DEPRESSION
Vitamin Deficiency:
Vitamin A, Retinoids
Deficiency:
- Night blindness (nyctalopia)
Vitamin B, Thiamine
Deficiency:
- Beri Beri - polyneuropathy, Wernicke-Korsakoff, heart F
Vitamin B3, Niacin
Deficiency:
- Pellagra - the 3Ds Dermatitis, Diarrhoea, Dementia
Vitamin B6, Pyridoxine
Deficiency:
- Anaemia, Irritabiliy, Seizures
Vitamin B7, Biotin
Deficiency:
- Dermatitis, Seborrhoea
Vitamin B9, Folic acid
Deficiency:
- Megaloblastic anaemia, Deficiency during pregnancy = Neural Tube Defects (NTDs)
Vitamin B12, Cyanocobalamin
Deficiency:
- Megaloblastic anaemia, Peripheral Neuropathy
Vitamin C, Ascorbic acid
Deficiency:
- Scurvy - Gingivitis, Bleeding
Vitamin D, Ergocalciferol, Cholecalciferol
Deficiency:
- Rickets, Osteomalacia
Best source of vit D = cod liver oil
Vitamin E, Tocopherol, Tocotrienol
Deficiency:
- Mild haemolytic anaemia in newborn infants, ataxia, peripheral neuropathy
Vitamin K, Napthoquinone
Deficiency:
- Haemorrhagic disease of the newborn, bleeding diathesis
Vitamin D
Vitamin D is a fat soluble vitamin that plays a key role in Ca2+ and phosphate metabolism
Sources:
- vitamin D2 (Ergocalciferol) = plants
- vitami D3 (Cholecalciferol) = dairy products and can be synthesised by the skin from sunlight
Functions:
- increase plasma calcium and plasma phosphate
- increase renal tubular reabsorption and gut absorption of calcium
- increase osteoclastic activity
- increase renal phosphate reabsorption
Consequences of Vit D deficiency:
- RICKETS - Children
- OSTEOMALACIA - Adults
Vitamin B12 Deficiency and SCDC - Example Question
A 67-year-old woman presents to her GP with progressive numbness and difficulty walking. Furthermore her daughter who was present mentions that she has been behaving strange over the past few months.
She is otherwise fit and well, apart from a ileal resection for treatment-resistant Crohn’s disease 9 years ago.
Laboratory tests showed a low haematocrit and mean corpuscular volume of 110 fL. Blood smear analysis noted macrocytic red blood cells with hypersegmented neutrophils.
Which of the following is the most likely cause of the patient’s presentation?
Ferrochelatase deficiency Folate deficiency Intrinsic factor deficiency Iron deficiency anaemia > Cobalamin deficiency
The ileal resection suggests that the patient is not absorbing the vitamin B12-intrinsic factor complex, leading to vitamin B12 deficiency (aka. cobalamin deficiency), and subsequently subacute combined degeneration. This is further supported by the macrocytic anaemia with hypersegmented neutrophils. Folate deficiency causes the same blood film picture but does not present with neurological symptoms.
Thallium Poisoning - Differentials = Vitamin Deficiencies
Thallium poisoning has also been mistaken for neurosyphilis and severe vitamin B deficiency. While neurosyphilis shares symptoms of confusion, fluctuating mood and palmar lesions as well as neuropathy, abdominal symptoms are usually not present and the diagnostic alopecia is absent in syphilis. Similarly, conditions such as Pellagra (niacin deficiency) and beriberi (thiamine deficiency) may share similar features with thallium poisoning such as alopecia, skin changes and mood disturbances, a painful neuropathy is less common; indeed sensory loss is more common in the extremities. Also in these conditions, the prime pathological aetiology is dietary deficiency.
Beri Beri Risk Factors (Thiamine Deficiency)
Alcohol dependency Renal dialysis Diet high in milled rice Longstanding Crohns - Malnourished Severe Hyperemesis Gravidarum in Pregnancy
Distinguishing Pellagra from Beri-Beri
Pellagra is distinguished from beriberi by the presence of a rash and gastrointestinal symptoms. Like beriberi, it can lead to confusion and memory deficits. 4Ds are not seen in Beri-Beri. Alcoholic patients may, of course, present with both. Other signs of Beri-Beri include dilated cardiomyopathy, oesophagitis and ataxia.
Osteomalacia Electrolytes
LOW Calcium, LOW Phosphate, LOW Vit D
High ALP
Elevated PTH 2dry to low Calcium and low Vit D
Sx = eg Proximal Myopathy
