# Association Between Iron Deficiency Anemia and Dental Caries in Children: A Systematic Umbrella Meta‐Analysis

## TL;DR

Children with iron deficiency anemia are more than three times as likely to have dental caries compared to those without anemia, according to a meta-analysis.

## Contribution

This study provides the first systematic umbrella meta-analysis linking iron deficiency anemia and dental caries in children.

## Key findings

- Children with IDA were over three times more likely to have dental caries (OR = 3.64).
- Lower ferritin levels in children with caries were observed but not statistically significant.
- The study suggests a possible bidirectional influence between iron deficiency and dental caries through multiple mechanisms.

## Abstract

Dental caries and iron deficiency anemia (IDA) are prevalent especially in developing children. There seems to be an association between these two variables.

To evaluate this association among children and adolescents using a systematic review and umbrella meta‐analysis technique.

The PRISMA reference databases like PubMed, Scopus, Web of Science and Google Scholar were searched for all records published before January 2025. Meta‐analyses that evaluated the association among < 18‐year‐olds were included. Parameters like odds ratio (OR) and mean difference (MD) with the 95% confidence interval (CI) were used to compare between the groups. I² and Cochran's Q (χ²) tests were used for measuring heterogeneity, whereas Egger's test was utilised to measure publication bias. A Measurement Tool to Assess systematic Reviews (AMSTAR 2) was used to assess the quality of the meta‐analyses. The degree of certainty of the outcomes was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool.

A total of five meta‐analyses were included. Children with IDA were significantly over three times more likely to have dental caries than children without anemia (OR = 3.64, 95% CI: 2.45 to 5.40, p < 0.0001. Heterogeneity: I² = 80%, p = 0.007. Publication bias: p = 0.14. GRADE: Moderate). The pooled analysis for serum ferritin showed a tendency toward lower ferritin level in children with caries; but without statistical significance (MD = −3.96, 95% CI: −8.48 to 0.57, p = 0.087. Heterogeneity: I² = 66.3%, p = 0.031. Publication bias: p = 0.003. GRADE: Very low). Children with dental caries had lower haemoglobin levels, but the finding was not significant with high level of heterogeneity and publication bias (MD = −2.20 g/dL, 95% CI: −4.59 to 0.19, p = 0.071. Heterogeneity: 80.%, p = 0.006. Publication bias: p = 0.005. GRADE: Very low). Children with caries had lower MCV, but this result was non‐significant with evidence of heterogeneity and publication bias (MD = −1.96 fL, 95% CI: −4.02 to 0.10, p = 0.062. Heterogeneity: I² = 57.2%, p = 0.096. Publication bias: p = 0.041. GRADE: Very low).

Dental caries was more prevalent among anemic children compared to non‐anemic ones with a low level of certainty.

Children with iron deficiency anemia were over three times more likely to have dental caries than children without anemia (OR = 3.64).Individual hematological parameters like haemoglobin, ferritin, and MCV showed non‐significant trends toward being lower in children with caries.The study proposes that iron deficiency and dental caries influence each other through impaired salivary function, reduced iron's antibacterial properties, dietary changes from tooth pain, and chronic inflammation.

Children with iron deficiency anemia were over three times more likely to have dental caries than children without anemia (OR = 3.64).

Individual hematological parameters like haemoglobin, ferritin, and MCV showed non‐significant trends toward being lower in children with caries.

The study proposes that iron deficiency and dental caries influence each other through impaired salivary function, reduced iron's antibacterial properties, dietary changes from tooth pain, and chronic inflammation.