August 11, 2015 - Microcytic and Microcytic Anemia

Question 1

Location of Folate Absorption

Answer 1

Only in the jejunum.

Question 2

Location of Cobalamin/B₁₂ Absorption

Answer 2

Only in the ileum.

Question 3

Location of Mg²⁺ Absorption

Answer 3

Only in the ileum.

Question 4

Ferritin

Answer 4

A protein that binds to and stores iron. It can be tested in a blood sample.

Question 5

Haemosiderin

Answer 5

The gold standard for determining iron levels in a patient, however it is only assessed by staining bone marrow with Prussian Blue and is therefore almost never used. Ferritin gives a good estimate and is significantly less invasive.

Question 6

Location of Iron Absorption

Answer 6

Mainly in the duodenum.

Question 7

Competitors for Iron Absorption

Answer 7

Include lead, cobalt, strontium, manganese, and zinc. These will out-compete iron and lead to poisoning of the individual.

Question 8

Facilitators of Iron Absoription

Answer 8

Ascorbate, citrate, amino acids, and iron deficiency will increase the amount of absorption.

Question 9

Causes for Iron Deficiency

Answer 9

1. Decreased iron intake (vegetarians)
2. Decreased iron absorption (celiac disease, Crohn’s disease etc.)
3. Increased iron loss (chronic bleeding)
4. Increased iron requirements (pregnancy / lactation)

Question 10

How much daily blood loss does it take to become iron deficient?

Answer 10

10 mL

Question 11

Symptoms of Iron Deficiency

Answer 11

Asymptomatic

Pallor

Irritability

Exercise intolerance

Fatigue

Tachycardia

Koilonychia (spoon nails)

Blue sclera

Question 12

Ferritin Test

Answer 12

The best screening test for iron deficiency anemia (not as invasive as haemosiderin). Low ferritin says iron deficient, although ferritin results may appear high in an acute inflammation.

Question 13

Treatment for Iron Deficiency

Answer 13

Oral iron. Start slow as to avoid constipation, nausea, and stomache cramps.

IM iron. Painful, but can deliver large doses.

IV iron. Needs to be done in hospital, takes many hours, and may cause serum sickness, fever, headache, or anaphylaxis.

Question 14

Other Causes of Microcytic Anemia

Answer 14

Thalassemia (problems with hemoglobin production)

Lead poisoning (rare)

ACD

Question 15

Over 50 and Anemic

Answer 15

You must rule out colorectal cancer before anything else.

Question 16

Causes of Folate Deficiency

Answer 16

Nutritional deficiency

Malabsorption

Drugs

Increased requirements

Question 17

Folate Deficiency

Answer 17

Can cause macrocytic and megaloblastic anemia.

Question 18

Folate Deficiency Diagnosis

Answer 18

Order a serum folate test.

Order a red blood cell folate test.

Question 19

Treatment of Folate Deficiency

Answer 19

Oral folate.

Question 20

Alcohol and Folate Absorption

Answer 20

Alcohol inhibits folate absorption.

Question 21

B12 Storage Capacity

Answer 21

Your body stores enough B₁₂ for years. This can be a problem with people going onto vegan diets as it will appear years later.

Question 22

Homocysteine and Methylmalonic Acid Test

Answer 22

Confirmatory tests with borderline B₁₂ test results.

Question 23

Diagnosis of B₁₂ Deficiency

Answer 23

Order a vitamin B₁₂ serum test.