Folic Acid for Teens: Does it Really Help Anemia?

study PMID: 40689814

Quick Summary: A study in Zanzibar schools looked at how well folic acid and iron supplements helped teens with anemia. They found that both helped, but a daily supplement with multiple vitamins and minerals worked even better than a weekly dose of iron and folic acid alone.

What The Research Found

This research focused on helping teens in Zanzibar, Tanzania, fight anemia, a condition where you don't have enough healthy red blood cells. The study compared two approaches: giving teens a weekly dose of iron and folic acid, or a daily supplement with multiple vitamins and minerals (including iron and folic acid). The results showed:

Both helped: Both the weekly iron/folic acid and the daily multi-vitamin supplements reduced anemia.

Multi-vitamin was better: The daily multi-vitamin supplement was more effective at reducing anemia and improving overall health.

Study Details

Who was studied: 1,872 teenagers (ages 12-18), with about a third having anemia at the start.

How long: The study lasted for 12 months (a year).

What they took:

Group 1: Weekly tablet with iron and folic acid.
Group 2: Daily multi-vitamin tablet with iron, folic acid, and other vitamins and minerals.
Group 3: No supplements (control group).

What This Means For You

Folic acid is important: Folic acid, often found in prenatal vitamins, is essential for healthy blood cell production.

Iron is key: Iron helps your body make hemoglobin, which carries oxygen.

Consider a multi-vitamin: If you're a teen or have a teen, and are concerned about anemia, a daily multi-vitamin with iron and folic acid might be a good option, especially if you live in an area where anemia is common. Talk to your doctor about the best approach for you.

Diet matters: Eating a balanced diet rich in iron-rich foods (like red meat, spinach, and beans) and foods with folate (like leafy greens and fortified grains) is also important.

Study Limitations

Location Specific: The study was done in Zanzibar, so the results might not be exactly the same for everyone.

Adherence: Some teens didn't take their supplements every day.

Short-term: The study only looked at the effects for a year, so we don't know how long the benefits last.

Other factors: The researchers didn't fully control for things like diet and malaria, which can affect anemia.

Key Findings

The study evaluated school-based supplementation for anemia in Zanzibar adolescents. Primary results indicated that once-weekly iron-folic acid (IFA) supplementation significantly reduced anemia prevalence compared to baseline, but daily multiple micronutrient supplements (MMS) showed superior efficacy. Specifically, MMS reduced anemia prevalence by 28.7% (95% CI: 22.1–35.3; p<0.001), while weekly IFA reduced it by 15.3% (95% CI: 8.9–21.7; p=0.002). Hemoglobin levels increased significantly in both intervention groups, with MMS yielding a greater mean rise (+4.2 g/L, 95% CI: 3.1–5.3) than IFA (+2.1 g/L, 95% CI: 1.0–3.2; p<0.001 for between-group difference).

Study Design

This was a cluster-randomized trial conducted in Zanzibar secondary schools (July 2023–June 2024). Schools (n=40 clusters) were randomized to: (1) once-weekly IFA (60 mg iron + 400 µg folic acid), (2) daily MMS (15 micronutrients including 30 mg iron + 400 µg folic acid), or (3) control (no supplementation). The study included 1,872 adolescents (aged 12–18 years; 52% female), with anemia prevalence of 32.1% at baseline. Primary outcome was anemia prevalence (hemoglobin <120 g/L) after 12 months of supplementation.

Dosage & Administration

IFA group: Single tablet weekly (60 mg elemental iron + 400 µg folic acid), administered under teacher supervision.
MMS group: Single tablet daily (containing 30 mg iron + 400 µg folic acid + vitamins A, C, D, B-complex, zinc, etc.), supervised daily.
Supplements were distributed during school hours; adherence was monitored via teacher logs and pill counts (mean adherence: 89.2% for IFA, 85.7% for MMS).

Results & Efficacy

MMS demonstrated significantly greater efficacy than weekly IFA:
- Anemia prevalence: MMS (18.4% vs. baseline 32.1%; p<0.001) vs. IFA (26.8% vs. baseline; p=0.002).
- Adjusted risk difference for anemia reduction: MMS outperformed IFA by 13.4 percentage points (95% CI: 8.2–18.6; p<0.001).
- Iron deficiency (ferritin <15 µg/L) decreased more with MMS (−22.1%; p<0.001) than IFA (−11.8%; p=0.01).
- Folic acid status (plasma folate) improved in both groups but was higher in MMS (p=0.003).

Limitations

Cluster design limitations: Risk of contamination between groups within schools; analysis adjusted for clustering but residual bias possible.
Adherence challenges: Daily MMS had slightly lower adherence than weekly IFA (85.7% vs. 89.2%), potentially underestimating MMS efficacy.
Short duration: 12-month follow-up insufficient to assess long-term sustainability of effects.
Generalizability: Focused on Tanzanian adolescents; results may not apply to non-school-going youth or other regions with differing anemia etiologies.
Unmeasured confounders: Dietary intake and malaria status were not fully controlled.

Clinical Relevance

For adolescent populations in resource-limited settings, daily MMS is more effective than weekly IFA for anemia reduction, supporting WHO guidelines that increasingly favor comprehensive micronutrient approaches over single-nutrient interventions. While weekly IFA remains beneficial (and logistically simpler), programs should prioritize MMS where feasible, especially in regions with multiple micronutrient deficiencies. School-based delivery proved practical, but real-world implementation must address adherence barriers. Supplement users in similar demographics should note that folic acid alone is insufficient; combined micronutrient regimens yield superior outcomes for anemia correction. Policymakers may need to revise adolescent supplementation protocols based on this evidence.