How is the transferrin saturation calculated?
First of all, a blood sample is required. For the sample to be taken, the patient must be fasting – in other words, he or she must not have eaten anything in the last eight to twelve hours and must have drunk no more than water or unsweetened tea.
The iron and transferrin levels in the blood serum of the sample are then determined in the laboratory. The transferrin saturation can be calculated from these values:
Transferrin saturation: Normal values
In children and adults, the following normal values for transferrin saturation apply:
|
Age |
Transferrin saturation: Normal value |
|
Preterm infants |
11,4 – 44,2 % |
|
1 day |
29,4 – 46,0 % |
|
2 to 7 days |
11,4 – 46,0 % |
|
8 to 14 days |
30 – 99 % |
|
15 days to 5 months |
10 – 43 % |
|
6 to 12 months |
10 – 47 % |
|
1 to 4 years |
7 – 44% |
|
5 to 9 years |
16 – 43 % |
|
10 to 13 years |
11 – 36 % |
|
14 to 17 years |
6 – 33 % |
|
from 18 years |
16 – 45 % |
When is the transferrin saturation too low?
If there is a severely reduced transferrin saturation of less than 10 percent, there is a severe iron deficiency with anemia. Common causes include:
- chronic blood loss (such as heavy menstrual bleeding or bleeding in the gastrointestinal tract)
- reduced iron absorption, for example due to malnutrition, celiac disease or chronic inflammatory bowel diseases such as Crohn’s disease
- increased iron requirements, for example during the growth phase or during pregnancy
An elevated value occurs in the context of iron overload. Such an overload exists, for example, in the hereditary disease hereditary hemochromatosis. An iron overload can also develop if someone receives a large number of blood transfusions within a short period of time.
