From the Guidelines

Hypoferritinemia in pediatrics should be treated when serum ferritin levels are less than or equal to 15 ug/L.

The diagnosis of iron deficiency (ID) in children relies on a combination of biochemical indicators, including serum ferritin, transferrin saturation (TSAT), and soluble Transferrin Receptor (sTfR) levels 1.
Serum ferritin is the mainstay for assessment of total body iron stores in children, and low ferritin levels are specific for ID 1.
However, ferritin lacks sensitivity for ID in inflammatory conditions, and the combined assessment and interpretation of ferritin and TSAT is useful in the diagnosis of absolute and functional ID 1.
The American Academy of Pediatrics guidelines recommend the use of reticulocyte Hb (RetHb) content parameters as an early marker for iron-restricted erythropoiesis due to ID before the development of anemia 1.

Screening for anemia is recommended for preterm infants and low-birthweight infants who are not fed iron-fortified infant formula before age 6 months 1.
In populations of infants and preschool children at high risk for iron-deficiency anemia, screen all children for anemia between ages 9 and 12 months, 6 months later, and annually from ages 2 to 5 years 1.
Iron supplementation strategies should be guided by the presence of iron deficiency, and the risks of ID versus risks of dysbiosis/perturbation of gut microbiota should be balanced, especially in premature and small-for-gestational age infants 1.

A serum ferritin concentration of less than or equal to 15 ug/L confirms iron deficiency, and treatment should be initiated at this threshold 1.

From the Research

Hypoferritinemia, or low serum ferritin levels, is a common nutritional disorder that affects a significant proportion of children, particularly in developing countries 2.
The diagnosis of iron deficiency, including hypoferritinemia, is crucial for optimal cognitive function and physical performance in children 2.
Serum ferritin levels are used to diagnose iron deficiency, and the cut-off values vary by age:
- For children from 6-12 years, a ferritin cut-off of 15 µg/l is recommended 2.
- For younger adolescents from 12-15 years, a cut-off of 20 µg/l is recommended 2.
- For children aged 1-3 years, the optimal serum ferritin cut-off values are still being determined, but a value of <12 μg/L has been suggested 3.
- For one-year-old children, a serum ferritin threshold of 24-25 μg/L has been proposed for iron deficiency screening 4.

Treatment of hypoferritinemia typically involves oral iron therapy, with a recommended dose of 2-3 mg/kg elemental iron daily 5.
Counselling and dietary modifications, such as increasing iron intake and avoiding inhibitors of iron uptake, are also important components of treatment 2.
In exceptional cases, intravenous iron injection may be necessary, such as in cases of concomitant disease or repeated failure of oral therapy 2.
Regular monitoring of serum ferritin levels and hemoglobin is essential to assess the effectiveness of treatment and prevent iron deficiency recurrence 2, 5.

Universal screening for anemia using hemoglobin is recommended at 12 months, but serum ferritin screening may be a more sensitive indicator of iron deficiency 3, 4.
Routine screening of infants for anemia at 9 months during immunization visits is recommended, along with age-appropriate iron-folic acid supplementation 5.
Prevention of anemia through dietary modifications, iron supplementation, and screening is crucial to reduce the prevalence of hypoferritinemia and iron deficiency anemia in children 2, 5.