Associations between Serum Iron Indices and Self-Assessed Multiple Intelligence Scores among Adolescents in Riyadh, Saudi Arabia

Micronutrient deficiencies, including iron deficiency, are linked to different cognitive impairments and sensory functions. However, whether circulating iron levels affect self-assessed multiple intelligence (MI) scores in adolescents remains uninvestigated. This study aimed to investigate associations between serum iron levels and self-assessed MI scores in adolescents in Riyadh, Saudi Arabia. Recruiting 434 Saudi adolescents (174 boys and 260 girls, aged 12–17), we administered the McKenzie questionnaire to assess MI across nine categories. Anthropometrics and fasting blood samples were collected to measure circulating iron and transferrin levels. Total iron-binding capacity (TIBC) and transferrin saturation (TSAT) levels were calculated. Notably, girls exhibited significantly higher MI scores in the interactive domain than boys (age and BMI-adjusted OR = 1.36, 95% confidence interval = 1.07–1.73, <i>p</i> = 0.01). No significant correlations were observed between serum iron and MI. However, normal TSAT levels (TSAT > 20%) corresponded with higher age and BMI-adjusted odds of MI scores in the musical (OR = 1.59, 95%CI = 1.1–2.2, <i>p</i> = 0.006), linguistic (1.57, 1.1–2.3, <i>p</i> = 0.016), kinesthetic (1.48, 1.1–2.1, <i>p</i> = 0.024), spatial (1.45, 1.1–2.1, <i>p</i> = 0.03), and existential (1.56, 1.1–2.1, <i>p</i> = 0.01) categories compared to ones with lower TSAT levels (TSAT ≤ 20%), only in boys. In conclusion, serum iron levels may not directly influence MI domains in adolescents in Riyadh, Saudi Arabia; however, lower TSAT levels, indicative of iron-deficiency anemia, may influence MI, only in boys, indicating a possible relationship between iron metabolism and cognitive functions.