Iron, B12 + folate

Question 1

Fe deficiency management

Answer 1

confirm iron deficiency anaemia
determine cause
treat anaemia
treat underlying

Question 2

What type of anaemia is Fe deficiency anaemia?

Answer 2

microcytic hypochromic
target cells present

Question 3

What type of anaemia is B12 deficiency anaemia?

Answer 3

macrocytic
(megaloblastic)

Question 4

What type of anaemia is folate deficiency anaemia?

Answer 4

macrocytic
(megaloblastic)

Question 5

Iron deficiency causes

Answer 5

Inadequate diet
Increased requirements (pregnancy, growth)
Malabsorption
Blood loss (menstrual, GI, urinary, lung)

Question 6

When should you do GI investigations in iron deficiency anaemia?

Answer 6

all men
all post-menopausal women
symptomatic women (eg. blood in stools)
women >45
FH colon cancer

Question 7

GI causes of iron deficiency anaemia

Answer 7

hookworm infections
oesophago-gastric cancer
coeliac disease
crohn’s disease
gastritis
peptic ulceration
oesophagitis
gastrectomy
NSAID enteritis
meckel’s diverticulum
colon cancer
large polyps
colitis
angiodysplasia
diverticular bleeding
haemorrhoids

Question 8

Describe iron replacement therapy

Answer 8

(continue for 3 months post Hb stabilisation)
oral ferrous sulphate
ferrous gluconate
sodium ironedetate
ferric maltol
avoid slow release preparations

Question 9

Describe folic acid

Answer 9

synthesised by bacteria
green veg, offal
biologically active as polyglutamates
small store
requires B12 for biological activity

Question 10

Describe vitamin B12

Answer 10

synthesised by microorganisms
stable to cooking
large store
essential to folate metabolism

Question 11

Describe B12 + folate deficiency

Answer 11

affects all cells
rapidly dividing cells most vulnerable (bone marrow precursors, gut epithelium)

Question 12

B12 deficiency symptoms

Answer 12

neuropathy
optic atrophy
fatigue
headaches
pallor
(can lead to neural tube defects, stroke and dementia)

Question 13

Fe deficiency symptoms

Answer 13

fatigue
weakness
fast/irregular heartbeat
chest pain
dizziness
restless legs syndrome
failure to thrive in infants
growth retardation in children
pallor
shortness of breath
brittle nails
cold hands + feet

Question 14

Folate deficiency symptoms

Answer 14

paraesthesia
mouth ulcers
tiredness

Question 15

Investigation + management of megaloblastic anaemia

Answer 15

confirm haematological diagnosis:
- blood film
- B12 + folate levels
- consider other macrocytosis causes
- bone marrow

provide replacement therapy
determine underlying cause

Question 16

Macrocytic anaemia megaloblastic causes

Answer 16

B12 deficiency
Folate deficiency
Combined deficiency
Abnormal folate metabolism (methotrexate)
Abnormal DNA synthesis (orotic aciduria, azathioprine, zidovudine)
Myelodysplasia

Question 17

Macrocytic anaemia non-megaloblastic causes

Answer 17

(not problem with cell division)
Just macrocytosis
Pregnancy
Liver disease
Alcoholism
Reticulocytosis
Hypothyroidism
Drugs
Marrow infiltration
Sideroblastic anaemia
Cold agglutinins

Question 18

Describe B12 replacement

Answer 18

Parenteral hydroxycobalamin
3 monthly replacement
prophylaxis after total gastrectomy or ileal resection
oral replacement if absorption intact (eg. vegans)

Question 19

Describe folate replacement

Answer 19

oral folic acid (4 months or continuously)
prophylaxis in pregnancy + preconception (reduce risk of neural tube defects)
prophylaxis for patients with haemolysis or on methotrexate

Question 20

In combined B12 and folate deficiency, which should be replaced first?

Answer 20

B12 then folate
initial folate may exacerbate neuropathy

Question 21

Folate deficiency causes

Answer 21

Diet (anorexia, children, elderly, alcoholics)

Increased utilisation:
- physiological = pregnancy, growth
- pathological = haemolysis, cancers, inflammation

Malabsorption (diffuse small bowel diseases)

Urinary loss (haemodialysis)

Drugs (phenytoin, primidone, sulfasalazine, methotrexate)

Question 22

B12 deficiency causes

Answer 22

Diet (vegan)

Gastric disease (Autoimmune gastritis, major gastrectomy)

Ileal disease (resection, inflammation)

Infections (small bowel bacterial overgrowth, Fish tapeworm)

Pancreatic disease

Transcobalamin-2 deficiency

B12 destruction (nitrous oxide)

Question 23

B12 deficiency investigations

Answer 23

dietary history
autoantibodies (anti-parietal cell, anti-intrinsic factor)
B12 absorption tests
small bowel FT + biopsy
gastric biopsy
gastric + pancreatic function tests

Question 24

Folate deficiency investigation

Answer 24

dietary history
autoantibodies (anti-gliadin, anti-endomysial)
duodenal biopsy
consider systemic diseases

Question 25

Vitamin B12 function

Answer 25

development, myelination, function of CNS RBC formation, DNA synthesis

Question 26

Folate function

Answer 26

RBC formation cell growth + function works with B6 + B12 to control elevated blood homocysteine

Question 27

Dietary sources of folate

Answer 27

liver yeast extract green leafy vegetables legumes (beans, lentils) orange juice fortified cereals

Question 28

Dietary sources of vitamin B12

Answer 28

Products of animal origin: - meat (especially liver) - poultry - fish - milk + dairy products - eggs fortified breakfast cereals fermented foods (eg. sauerkraut)

Question 29

Vulnerable groups for nutritional anaemias

Answer 29

Infants + young children (iron) Vegans (iron + B12) Pregnant women (iron + folate) Elderly (iron, folate + B12) Low income Ethnic minorities

Question 30

Signs of iron deficiency in infants

Answer 30

poor weight gain frequent infections developmental delay behavioural disorders

Question 31

Why is anaemia more common in the elderly?

Answer 31

impaired absorption (particularly B12) dental problems (restricted food choice) poor quality meals in institutions lower socioeconomic status less mobile (restricted shopping) mental problems (dementia, depression) lower physical activity requires lower energy intake (less chance of taking in adequate nutrients)

Question 32

Why can serum folate levels be unreliable?

Answer 32

a single meal containing folate can rapidly elevate serum folate levels must do further tests if folate levels are borderline

Question 33

Ferrous sulphate side effects

Answer 33

metallic taste constipation black, tarry stools

Question 34

Anaemia of chronic disease features

Answer 34

Normochromic, normocytic or mildly hypochromic mild + non-progressive anaemia serum iron and TIBC reduced serum ferritin normal/platelets Transferrin saturation low