Assessment of Nutritional Status - Biochemical (iron deficiency anaemia, calcium status, and vitamin status) Flashcards
What is the most common cause of anaemia?
iron deficiency
briefly describe the mechanism behind iron deficiency anaemia
iron is an integral part of healthy red blood cells
lack of iron = lack of oxygen being carried around the body
lack of oxygen to cells causes tiredness and fatigue
What are some clinical symptoms of iron deficiency anaemia?
fatigue weakness pale skin dizziness shortness of breath cold hands/feet
what are some pathophysiological consequences of iron deficiency?
low oxygen storage low haemoglobin (anaemia) mitochondrial dysfunction low energy efficiency low exercise capacity
what are the biochemical markers used to diagnose iron deficiency anaemia?
- haemoglobin
- hematocrit
- transferrin
- serum iron
- serum ferritin
- mean corpuscular value (MCV)
- total iron binding capacity (TIBC)
what is haemoglobin?
iron containing molecule that carries oxygen in red blood cells
What is haemodilution
Increase in plasma volume (usually seen in pregnancy) that causes haemoglobin level to decrease
What does a hematocrit test measure?
the percentage of red blood cells making up the volume of the blood
depends on:
number and size of RBC’s
Describe transferrin and it’s role in the body
transferrin is a glycoprotein that binds to iron for transportation around the body
How does transferrin level diagnose iron deficiency anaemia?
Levels of transferrin increase in ppt with iron deficiency anaemia
what is serum iron a measure of?
the measure of the amount of iron bound to transferrin
what is serum ferritin?
the primary storage form of iron in the body
which is the most effective biochemical test for iron deficiency anaemia?
Serum ferritin test
describe the term ‘anaemia’.
anaemia is below normal levels of haemoglobin
describe microcytic anaemia
Below average sized red blood cells
describe macrocytic anaemia
abnormally large red blood cells
most common form of macrocytic anaemia is megaloblastic anaemia.
describe hypochromic anaemia
abnormal level of haemoglobin
red blood cells are paler than usual
often overlaps with microcytic anaemia as RBC are usually small too
which biochemical test would you do in the 1st stage of iron deficiency?
what would it show?
serum ferritin test
would show a decreased level of serum ferritin as iron store depletes
which biochemical test would you do in the 2nd stage of iron deficiency?
what would it show?
transferrin test
transferrin level will increase
which biochemical tests would you do in the 3rd stage of iron deficiency?
haemoglobin test - Hb levels decreased
MCV test - levels decreased
serum ferritin test - level decreased
how is calcium status measured?
there is no biochemical test to measure calcium status
this is because 99% calcium in the body is in the bones
DEXA scan to assess bone health with give indication of Ca store
Describe a static and functional test used to assess vitamin A status
Static - serum or breast milk Vit A concentration
Functional - dark adaptation test
why is serum vitamin C not an accurate measure of total body Vit C status?
what is measured as an alternative?
serum Vit C level reflects dietary intake of vitamin C
leukocyte level of Vit C is measured to more accurately reflect the pool of Vit C in the body
How is vitamin B12 deficiency measured?
MCV test
Hb test
once a vitamin B12 deficiency is recognised, what test is used to determine the cause?
Schilling test
What are some important roles of calcium in the body?
blood clotting
tooth and bone formation
muscle contraction
cell membrane structure
What are some important roles of Vitamin C in the body?
promotes iron absorption antioxidant protects against cancer protects against scurvy formation of collagen
