The range of normal ferritin in most laboratories is 30 ng/mL to 300 ng/mL, and the mean is 49 ng/mL in women. The National Health and Nutrition Examination Survey describes iron deficiency in women as a low concentration of ferritin (<12 ng/mL). Diagnosis prompts consideration of the cause of IDA (usually, bleeding).
Although the transferrin level is increased, the serum iron level decreases; transferrin saturation decreases. Erythropoiesis is impaired when serum iron falls to < 50 mcg/dL (< 9 micromol/L) and transferrin saturation to < 16%.
Iron deficiency is diagnosed when ferritin is <30μg/L in adults and < 20μg/L in children. When ferritin is not elevated as an acute phase reactant, a value >30μg/L is normal.
At serum ferritin levels less than about 20µg/L, the tissues and cells are not receiving the iron they need to function correctly (stage two or latent iron deficiency). The final and most severe stage is iron-deficiency anaemia.
Normal Results
Normal value range is: Iron: 60 to 170 micrograms per deciliter (mcg/dL), or 10.74 to 30.43 micromoles per liter (micromol/L) Total iron binding capacity (TIBC): 240 to 450 mcg/dL, or 42.96 to 80.55 micromol/L.
In women of reproductive age, heavy periods and pregnancy are the most common causes of iron deficiency anaemia as your body needs extra iron for your baby during pregnancy. Unless you're pregnant, it's rare for iron deficiency anaemia to be caused just by a lack of iron in your diet.
The normal range for men is 13.5 to 17.5g/dL. For women, the normal range is 12.0 to 15.5g/dL. African American men and women will have a normal range that varies by 0.7g/dL at the low end of the range.
Iron-Rich Foods
Heme iron is found in meat, fish and poultry. It is the form of iron that is most readily absorbed by your body. You absorb up to 30 percent of the heme iron that you consume. Eating meat generally boosts your iron levels far more than eating non-heme iron.
You may also find that low iron causes weight gain. There are a couple of reasons for this; firstly, your energy levels are low and so your exercise levels reduce; secondly, iron is essential for thyroid function, and an underactive thyroid will lead to weight gain.
Your body relies on iron to make hemoglobin, so when iron is low, you can become anemic. Your cells don't receive enough oxygen, and you feel tired. “The most frequent symptom of iron-deficiency anemia is fatigue,” says Kathryn Boling, MD, a family doctor at Mercy Medical Center in Baltimore.
Low red blood cells – hemoglobin level less than 120 g/L (grams per litre).
Undiagnosed or untreated iron-deficiency anemia may cause serious complications such as fatigue, headaches, restless legs syndrome, heart problems, pregnancy complications, and developmental delays in children. Iron-deficiency anemia can also make other chronic conditions worse or cause their treatments to work poorly.
– It usually takes 2 to 3 weeks of taking regular iron supplements before your symptoms start to improve. – You may need to keep taking iron for several months to build up your iron reserves and keep your anemia from returning. Take your pills for as long as your doctor recommends, even if your symptoms have improved.
The WHO defines low ferritin as levels <15 μg/L for adults and <12 μg/L for children. However, in clinical practice, when ferritin levels dip below 30 μg/L, ID can be ascertained. Ferritin is an acute-phase reactant that is increased in serum during chronic inflammation.
Another measurement, called transferrin saturation, checks how many places on your transferrin that can hold iron are actually doing so. Normal values are 15% to 50%. In severe cases of iron-deficiency and anemia, this number may fall below 10%.
"Iron deficiency often causes only mild symptoms, but — left undiagnosed and untreated — it can affect a person's quality of life and, while rare, even be a sign of a serious health issue."
A large 2020 study in BMC Psychiatry found that people with iron deficiency anemia had a significantly higher incidence and risk of anxiety disorders, depression, sleep disorder, and psychotic disorders.
Iron Intakes and Status
The average daily iron intake from foods and supplements is 13.7–15.1 mg/day in children aged 2–11 years, 16.3 mg/day in children and teens aged 12–19 years, and 19.3–20.5 mg/day in men and 17.0–18.9 mg/day in women older than 19.
Many laboratories consider serum ferritin levels greater than 200 ng/mL in women and greater than 300 ng/mL in men to be abnormal.
Eye symptoms of low iron can include a pale coloring of the inside of the lower eyelids. In moderate or severe cases of iron deficiency anemia, the inside layer of the lower eyelid is very pale pink or yellow instead of red. Rather than low iron, one common cause of blurry vision is dry eye.