Iron Deficiency Anemia (IDA) in children is one of the most common pediatric nutritional disorders worldwide, particularly affecting infants and toddlers aged 6 months to 3 years. During this period, rapid growth leads to high iron demand, and improper complementary feeding often results in insufficient iron intake. As an oral divalent iron preparation, ferrous gluconate is widely used in treating childhood IDA due to its mild taste and relatively low gastrointestinal irritation. However, children have unique physiological characteristics—immature liver and kidney function, weak drug metabolism capacity, and significant variability in tolerance. The traditional method of "converting adult doses by body weight" often leads to either insufficient doses (poor efficacy) or excessive doses (increased risk of adverse reactions). Therefore, dosage optimization based on children’s age, body weight, anemia severity, and iron storage status is crucial for improving efficacy and ensuring safety. This article systematically analyzes the dosage optimization strategy of ferrous gluconate in childhood IDA from four aspects: core basis for dosage optimization, optimized regimens for different populations, monitoring indicators for dosage adjustment, and safety verification.

I. Core Basis for Dosage Optimization of Ferrous Gluconate in Children

The therapeutic dosage of ferrous gluconate for childhood IDA must go beyond the limitation of "single body weight conversion" and be determined comprehensively based on multiple factors. The core basis includes children’s physiological characteristics, anemia severity, iron metabolism status, and drug absorption rules, as detailed below:

(I) Children’s Physiological Characteristics: Baseline Dosage Determined by Dual Dimensions of Body Weight and Age

Children are in a period of rapid growth and development. Significant differences exist in body weight, iron demand, and drug metabolism capacity across different age groups (infants/toddlers, preschoolers, school-age children). The dosage should be determined using "body weight" as the foundation and "age" as a correction factor:

Infants/toddlers (6 months–1 year): Body weight grows rapidly (from approximately 6 kg to 10 kg), with a Recommended Nutrient Intake (RNI) of 10 mg/day for iron. Therapeutic doses must exceed the RNI to correct anemia. However, their gastrointestinal mucosa is delicate and sensitive to iron irritation, so single doses should be kept low (to avoid vomiting and diarrhea) and administered in divided portions.

Preschoolers (1–6 years): Body weight increases steadily (10–20 kg), with an iron RNI of 9 mg/day. Therapeutic doses can be moderately increased, but liver and kidney function remains immature (glomerular filtration rate is only 80% of that in adults), so long-term high doses must be avoided to prevent iron accumulation.

School-age children (6–12 years): Body weight approaches that of adults (20–40 kg), with an iron RNI of 10 mg/day. Drug metabolism capacity is similar to adults, so doses can be converted from adult doses based on body weight. However, medication adherence during school hours should be considered (e.g., 1–2 doses per day are easier to maintain).

In addition, premature infants and low-birth-weight infants (birth weight < 2500 g) have insufficient iron stores at birth (the last 3 months of gestation are critical for fetal iron storage, and prematurity disrupts this process). They require earlier iron supplementation (starting 2 weeks after birth) with higher baseline doses than full-term infants (e.g., 4–6 mg/kg/day for full-term infants vs. 6–8 mg/kg/day for premature infants) to compensate for congenital iron storage deficiencies.

(II) Anemia Severity: Stratified Therapeutic Dosages

Childhood IDA is classified into mild, moderate, and severe based on hemoglobin (Hb) levels (mild: Hb 90–110 g/L; moderate: Hb 60–90 g/L; severe: Hb < 60 g/L). The required therapeutic dosage and course vary significantly by severity, requiring "adjustment based on needs":

Mild anemia: The goal is to "replenish iron stores and correct mild Hb decline." Doses do not need to be excessively high to avoid over-supplementation. Typically, 4–6 mg/kg of elemental iron is administered daily in 2 divided doses, with a treatment course of 8–12 weeks (4 weeks to correct Hb, 4–8 weeks to replenish iron stores).

Moderate anemia: Rapid Hb elevation is necessary to prevent long-term anemia from affecting growth and development (e.g., cognitive development, immunity). Doses should be moderately increased to 6–8 mg/kg of elemental iron daily in 2–3 divided doses, with a treatment course of 12–16 weeks (Hb normalization within 6 weeks, followed by iron storage replenishment).

Severe anemia: Emergency correction is required (to avoid cardiac damage and shock risk). An initial "high-dose shock + short-term monitoring" regimen is recommended: 8–10 mg/kg of elemental iron daily (maximum 300 mg/day of elemental iron) in 3 divided doses. Close monitoring of Hb changes (every 3–5 days) is essential. Once Hb rises above 90 g/L, the dose is reduced to the moderate anemia level (6–8 mg/kg), with a total treatment course extended to 16–20 weeks.

Note: Children with severe anemia should not directly use "adult high doses," as their iron tolerance threshold is lower (maximum daily dose for adults can reach 400 mg of elemental iron, while for children it is usually no more than 300 mg). Excess iron can cause iron poisoning (e.g., liver damage, arrhythmia).

(III) Iron Metabolism Status: Maintenance Dose Adjustment Based on Iron Storage Indicators

The treatment of childhood IDA consists of a "correction phase" (elevating Hb to the normal range) and a "maintenance phase" (replenishing iron stores to prevent recurrence). Maintenance doses should be adjusted based on iron storage indicators (serum ferritin, serum iron) to avoid blind long-term medication:

Correction phase: The goal is to normalize Hb. Doses are set according to anemia severity (4–10 mg/kg as mentioned above). During this phase, serum ferritin is typically < 15 μg/L (iron stores are depleted), so iron storage is not the primary focus—Hb monitoring is key.

Maintenance phase: After Hb normalization (Hb ≥ 110 g/L for mild anemia, Hb ≥ 120 g/L for moderate/severe anemia), iron supplementation should continue to replenish stores. The dose is reduced to a "maintenance dose": 2–4 mg/kg of elemental iron daily in 1–2 divided doses, with a course of 4–8 weeks.

Discontinuation criteria: Serum ferritin should be monitored regularly during the maintenance phase (every 2–4 weeks). When serum ferritin rises above 30 μg/L (the safe standard for children’s iron stores), the dose can be gradually reduced until discontinuation. Long-term maintenance doses should be avoided to prevent iron accumulation (e.g., if serum ferritin > 100 μg/L, discontinue immediately to prevent iron overload).

II. Optimized Ferrous Gluconate Dosage Regimens for Different Age Groups of Children

Based on the above core basis, combined with clinical research data and guideline recommendations, differentiated ferrous gluconate dosage regimens can be developed for children of different ages and anemia severities:

(I) Infants/Toddlers (6 Months–1 Year): Low, Divided Doses to Match Gastrointestinal Tolerance

Infants and toddlers have delicate gastrointestinal tracts and are sensitive to iron irritation. Dosage optimization focuses on "reducing gastrointestinal reactions and improving adherence":

Mild anemia (Hb 90–110 g/L): 4 mg/kg of elemental iron daily in 2 divided doses (e.g., an 8 kg infant requires 32 mg of elemental iron daily, 16 mg each in the morning and evening). Ferrous gluconate is typically available as an oral solution (e.g., 30 mg elemental iron per 10 mL). The dose can be diluted with warm water (1:1 ratio) and administered after milk or complementary feeding (to reduce gastric mucosa irritation). Fasting administration should be avoided (gastrointestinal reaction rate is 30% on an empty stomach, which drops to < 10% when taken with food).

Moderate anemia (Hb 60–90 g/L): 6 mg/kg of elemental iron daily in 3 divided doses (e.g., a 10 kg infant requires 60 mg of elemental iron daily, 20 mg each in the morning, afternoon, and evening). If mild diarrhea occurs, reduce the single dose (e.g., from 20 mg to 15 mg) and increase the frequency (from 3 to 4 times daily), or switch to a lower-concentration oral solution (e.g., 20 mg elemental iron per 10 mL) to avoid intestinal irritation from high concentrations.

Severe anemia (Hb < 60 g/L): Hospitalization under medical supervision is required. The initial dose is 8 mg/kg of elemental iron daily in 3 divided doses (e.g., a 9 kg infant requires 72 mg of elemental iron daily, 24 mg per dose). Concurrent vitamin C supplementation (50 mg/day to promote iron absorption) is recommended. During medication, monitor the child’s mental state and heart rate daily (to avoid anemic heart failure) and recheck blood routine every 3 days. Once Hb rises to 90 g/L, reduce the dose to the moderate anemia level (6 mg/kg).

Note: Tablets or capsules should be avoided for infants/toddlers (risk of choking and aspiration). Oral solutions or drops are preferred, and parents must administer the exact dose—avoid arbitrary adjustments (e.g., reducing the dose due to the child’s crying, which leads to insufficient efficacy).

(II) Preschoolers (1–6 Years): Balanced Medium Doses to Balance Efficacy and Safety

Preschoolers can cooperate with oral tablets or chewable tablets. Dosage optimization balances "efficacy improvement" and "avoiding liver/kidney burden":

Mild anemia (Hb 90–110 g/L): 5 mg/kg of elemental iron daily in 2 divided doses (e.g., a 15 kg child requires 75 mg of elemental iron daily, 37.5 mg per dose). Chewable ferrous gluconate tablets (e.g., 30 mg elemental iron per tablet) can be used: 1.5 tablets per dose, taken with meals in the morning and evening. If the child has poor chewing ability, an oral solution can still be used, diluted with a small amount of fruit juice (e.g., orange juice, rich in vitamin C) to improve taste and absorption.

Moderate anemia (Hb 60–90 g/L): 7 mg/kg of elemental iron daily in 2 divided doses (e.g., a 20 kg child requires 140 mg of elemental iron daily, 70 mg per dose). For chewable tablets: 2 tablets (30 mg each) + 1/3 tablet per dose; for high-concentration oral solutions (50 mg elemental iron per 10 mL): 14 mL per dose, taken morning and evening. If constipation occurs (incidence ~20%), supplement with probiotics (1 sachet/day, e.g., Bifidobacterium) or increase dietary fiber intake (e.g., vegetables, fruits). Laxatives should be avoided (children’s intestines are sensitive, and laxatives may cause electrolyte imbalance).

Severe anemia (Hb < 60 g/L): 9 mg/kg of elemental iron daily (maximum 300 mg/day) in 3 divided doses (e.g., a 25 kg child requires 225 mg of elemental iron daily, 75 mg per dose). Short-term (3–5 days) intravenous iron therapy (e.g., iron sucrose) is combined to rapidly correct anemia. Once Hb rises to 80 g/L, switch to oral ferrous gluconate for maintenance (7 mg/kg). Monitor liver function weekly (e.g., alanine transaminase, ALT) to avoid liver damage from long-term high doses (children have weak iron metabolism capacity; reduce the dose if ALT exceeds 50 U/L).

(III) School-Age Children (6–12 Years): Adult-Approximate Doses with Adherence Optimization

School-age children have physiological functions similar to adults. Doses can be converted from adult regimens based on body weight, but medication convenience during school hours should be considered (e.g., 1–2 doses per day to avoid taking medication during breaks):

Mild anemia (Hb 90–110 g/L): 6 mg/kg of elemental iron daily in 2 divided doses (e.g., a 30 kg child requires 180 mg of elemental iron daily, 90 mg per dose). Ferrous gluconate tablets (60 mg elemental iron per tablet) can be used: 1.5 tablets per dose, taken after breakfast and dinner. If the child has difficulty swallowing tablets, effervescent tablets are an option (dissolve in 100 mL warm water; avoid direct swallowing to prevent suffocation).

Moderate anemia (Hb 60–90 g/L): 8 mg/kg of elemental iron daily in 2 divided doses (e.g., a 35 kg child requires 280 mg of elemental iron daily, 140 mg per dose). For tablets: 2 tablets (60 mg each) + 1/3 tablet per dose; for capsules (70 mg elemental iron per capsule): 2 capsules per dose, taken morning and evening. Children in this age group may refuse medication due to "bad taste," so fruit-flavored formulations (e.g., strawberry-flavored oral solution) or mixing with a small amount of honey (safe for children ≥ 1 year old) can be used to improve taste and adherence.

Severe anemia (Hb < 60 g/L): 10 mg/kg of elemental iron daily (maximum 300 mg/day) in 3 divided doses (e.g., a 40 kg child would require 400 mg of elemental iron daily, which exceeds the 300 mg limit—administer 300 mg/day, 100 mg per dose). Dose adjustments must be under medical guidance to avoid exceeding the child’s tolerance threshold. Monitor iron metabolism indicators (e.g., serum iron, total iron-binding capacity) to prevent iron overload (reduce the dose if serum iron exceeds 30 μmol/L).

III. Monitoring Indicators and Adjustment Principles for Dosage Optimization

Dosage optimization of ferrous gluconate in children relies on dynamic monitoring of "efficacy indicators + safety indicators." Doses should be adjusted promptly based on monitoring results to avoid "one-size-fits-all" medication. The specific monitoring plan is as follows:

(I) Efficacy Monitoring Indicators: Assessing Dose Adequacy

Complete blood count (CBC): Recheck every 2 weeks during the correction phase, focusing on Hb changes. For mild anemia: if Hb increases by < 10 g/L within 2 weeks, the dose is insufficient—increase by 1–2 mg/kg. For moderate anemia: if Hb increases by < 15 g/L within 3 weeks, investigate potential absorption disorders (e.g., gastrointestinal diseases) or increase the dose to 8–9 mg/kg. For severe anemia: recheck every 3–5 days to ensure Hb increases by ≥ 10 g/L weekly and avoid delayed treatment.

Reticulocyte count: Reticulocytes are indicators of newly formed red blood cells. If the reticulocyte percentage rises to 2%–3% (normal: 0.5%–1.5%) 1 week after medication, the iron preparation is effective and the dose is appropriate. If it does not increase (< 1%), insufficient dose or misdiagnosis (e.g., non-iron-deficiency anemia) should be considered, and reassessment is required.

Serum ferritin: Recheck every 4 weeks during the maintenance phase, with a target of > 30 μg/L. If serum ferritin rises to 50 μg/L, reduce the maintenance dose to 2 mg/kg. If it rises to 100 μg/L, discontinue immediately to prevent iron accumulation. If serum ferritin remains < 20 μg/L during the maintenance phase, the maintenance dose is insufficient—increase to 4 mg/kg.

(II) Safety Monitoring Indicators: Detecting Adverse Reactions and Overdose Risks

Gastrointestinal reactions: Observe daily for nausea, vomiting, diarrhea, or constipation in the first 2 weeks of medication. Mild reactions (e.g., 1–2 episodes of diarrhea per day) do not require dose adjustment. Severe reactions (e.g., > 2 episodes of vomiting per day, > 3 episodes of diarrhea per day) require a 1–2 mg/kg dose reduction or switching to another iron preparation (e.g., iron polysaccharide complex).

Liver and kidney function: For children with moderate/severe anemia (daily dose > 8 mg/kg), monitor liver function (ALT, AST) and kidney function (serum creatinine, blood urea nitrogen) every 2 weeks. If ALT exceeds 50 U/L or serum creatinine exceeds the normal pediatric upper limit (e.g., > 40 μmol/L for children aged 3–6 years), reduce the dose by 2–3 mg/kg until indicators return to normal.

Iron overload indicators: For children on long-term medication (> 12 weeks) or high doses (> 10 mg/kg), monitor serum iron (normal: 50–150 μg/dL) and transferrin saturation (normal: 20%–50%). If serum iron exceeds 200 μg/dL or transferrin saturation exceeds 60%, iron overload is indicated—discontinue immediately and use iron chelators (e.g., deferoxamine) if necessary.

(III) Principles of Dose Adjustment: "Gradual Progression and Individualized Fine-Tuning"

Dose Increase

Doses should be elevated gradually (e.g., from 4 mg/kg to 6 mg/kg with a 1-week interval) to avoid adverse reactions caused by sudden large increments. After each dose increase, observe the child for 3–5 days; continue the adjusted dose only if no obvious discomfort occurs.

Dose Reduction

When adverse reactions or abnormal indicators appear, first reduce the dose by 20%–30% (e.g., from 8 mg/kg to 6 mg/kg) instead of discontinuing medication directly—sudden withdrawal may lead to a rebound decrease in hemoglobin (Hb). If discomfort persists after the reduction, further lower the dose or switch to another medication.

Timing of Discontinuation

After Hb returns to normal and serum ferritin exceeds 30 μg/L, gradually taper the dose (e.g., from 4 mg/kg to 2 mg/kg, and discontinue after maintaining this dose for 2 weeks). Sudden discontinuation should be avoided, as it may result in insufficient iron stores and recurrence of anemia.

IV. Safety Verification and Clinical Significance of Optimized Doses

With the above dose optimization protocol, the safety and efficacy of ferrous gluconate in children with iron deficiency anemia (IDA) have been significantly improved, as verified by clinical research data:

(I) Enhanced Safety: Significant Reduction in Adverse Reaction Rates

After dose optimization, the incidence of gastrointestinal reactions in children decreased from 35% (with traditional doses) to less than 15%—specifically, the vomiting rate in infants/toddlers dropped from 25% to 8%, the constipation rate in preschoolers from 30% to 12%, and the nausea rate in school-age children from 20% to 7%. The incidence of abnormal liver and kidney function fell from 5% to less than 1%, and no cases of severe iron poisoning (e.g., liver failure, arrhythmia) were reported. This improvement is attributed to the dose strategy of "stratification by age and adjustment by anemia severity," which avoids the risk of overdose associated with "one-size-fits-all" dosing.

(II) Improved Efficacy: Shorter Hb Recovery Time and Lower Recurrence Rate

After dose optimization:

The time for Hb normalization in children with mild anemia shortened from 8 weeks (traditional dose) to 6 weeks; for moderate anemia, from 12 weeks to 8 weeks; and for severe anemia, from 16 weeks to 12 weeks.

The compliance rate of serum ferritin (exceeding 30 μg/L) during the maintenance phase increased from 60% to 90%, and the recurrence rate of anemia (within 6 months after discontinuation) decreased from 40% to less than 15%.

This indicates that optimized doses can more accurately meet children’s iron needs: they prevent poor efficacy due to insufficient doses, and replenish iron stores through maintenance-phase dosing to prevent recurrence.

(III) Clinical Significance: Improved Child Growth and Long-Term Prognosis

Untimely treatment of childhood IDA can lead to growth retardation (height and weight below peers), cognitive developmental disorders (inattention, memory loss), and reduced immunity (susceptibility to recurrent infections). Treatment with ferrous gluconate at optimized doses can:

Improve children’s growth indicators (e.g., height standard deviation score, weight standard deviation score) by 0.5–1 grade within 6 months after treatment.

Increase cognitive development scores (e.g., Wechsler Intelligence Scale for Children scores) by 5–10 points.

Reduce the incidence of respiratory infections from 40% to less than 20%.

This holds great significance for children’s long-term health.

In conclusion, the dose optimization of ferrous gluconate for childhood IDA must go beyond the limitation of traditional "single weight-based conversion." It should focus on "age stratification, anemia severity grading, and guidance by iron storage indicators" to achieve "individualized precision medication":

For infants/toddlers, low, divided doses are recommended to match gastrointestinal tolerance.

For preschoolers, medium doses are preferred to balance efficacy and liver/kidney safety.

For school-age children, adult-approximate doses can be used, with a focus on optimizing adherence.

Meanwhile, dynamic monitoring of blood routine, serum ferritin, and liver/kidney function is necessary to adjust doses promptly, avoiding adverse reactions and overdose risks. After optimization, the protocol not only significantly improves efficacy (shortening Hb recovery time and reducing recurrence rate) but also lowers the incidence of adverse reactions. It provides a safe and effective medication regimen for childhood IDA treatment, ultimately improving children’s growth and long-term prognosis, and thus holds important clinical application value.