Iron is a mineral that your body obtains through foods such as red meat, spinach, red kidney beans, edamame beans, chickpeas fortified cereals and supplements. Iron helps in producing blood cells. Haemoglobin, a protein in blood that helps transfer oxygen from the lungs to the rest of the body, contains iron.
Haemoglobin molecules in red blood cells bind 65% of the iron in the body. Myoglobin molecules bind about 4% of the total. In the spleen, bone marrow, and liver, about 30% of the iron in the body is stored as ferritin or hemosiderin. Iron is also present in minute levels in other compounds in cells all over the body. By evaluating the serum, none of this iron is directly available.
A blood test for iron can reveal if the body has too much or too little of this element in the body. It can detect disorders such as anaemia and iron overload (Hemochromatosis). If you exhibit symptoms of either condition, you should undergo a blood test.
Low iron causes the following symptoms:
- Lightheaded, faint, or as if the head is spinning, with a distorted sense of balance and position.
- Frequent headaches
- Pallor (Jaundice)
- Shortness of breath (Emphysema)
High iron levels might cause the following symptoms:
- Joint discomfort
- Feeling low on energy
- Stomach ache
Type of Iron Blood Tests
There are several different tests to check the level of iron in the body. These tests evaluate how much of the iron is moving through your blood, how well the blood carries it, and how much iron is stored in tissues.
- Serum iron– This test measures the amount of iron in your blood.
- Serum ferritin-This test measures how much iron is stored in your body. When your iron level is low, your body will pull the iron out of “storage” to use.
- Total iron-binding capacity (TIBC)– This test suggests how much transferrin (a protein) is free to carry iron through your blood. If the TIBC level is high, it means more transferrin is free because you have low iron.
- Unsaturated iron-binding capacity (UIBC)-This test measures how much transferrin isn’t attached to iron.
- Transferrin saturation– This test measures the percentage of transferrin that is attached to iron.
A low iron level is due to:
- A lack of iron in the diet
- Trouble absorbing iron from foods you eat. For E.g in celiac disease
- Blood leaking from a ruptured blood vessel, either within or outside the body. (Hemorrhage)
- During gestation
A lack of iron can affect your body’s ability to make red blood cells. If your iron level is too low, you could have iron deficiency anaemia. This suggests that the body doesn’t have enough healthy red blood cells to transport oxygen to your organs and tissues.
A high iron level is due to:
- Taking too many iron supplements within a short period of time.
- Hemochromatosis; is a condition that makes it harder for your body to remove excess iron
- Blood transfusions (In case of an accident or Haemophilia, anaemia or cancer, Leukemia etc.)
The following are typical reference ranges:
Serum iron: 65-176 g/dL in men
50-170 g/dL in women
100-250 g/dL in newborns
50-120 g/dL in children
Serum ferritin: In men, 24-336 micrograms per litre
For women, it is 11-307 micrograms per litre
Total iron-binding capacity (TIBC): 240-450 g/dL
Unsaturated iron-binding capacity (UIBC): 255-450 μg/dL
Saturation of transferrin: 20–50%
Routine analytical measures and results for evaluating the iron status, iron deficiency, and related conditions (such as iron-refractory iron deficiency anaemia (IRIDA) and chronic illness anaemia) are well established.
The most sensitive and specific test for detecting iron deficiency (indicated by a level of 30 g per litre) is the serum ferritin level. Patients with iron deficiency anaemia have lower levels; a transferrin saturation of less than 16 per cent shows that the iron supply is insufficient to maintain normal erythropoiesis.
However, rather than relying on specific test findings when establishing iron status, it’s necessary to look at the big picture. A recent study of the differential diagnosis of microcytic anaemias was published elsewhere. Iron-deficiency anaemia in the context of inflammation is difficult to diagnose and cannot be determined based on the results of a single test. Significantly higher ferritin cutoff levels define iron-deficiency anaemia in the context of inflammation, with a ferritin level of less than 100 g per litre being the best predictor.
In other cases, higher ferritin cutoff levels are used to diagnose iron insufficiency (e.g., 300 g per litre for heart failure and chronic kidney disease in the presence of a transferrin saturation level of less than 30%). Iron staining of bone marrow specimens obtained by biopsy is a rarely utilised technique for assessing iron reserves.