Iron deficiency without anemia is associated with anger and fatigue in young Japanese women

Iron deficiency without anemia (IDNA), the most prevalent nutritional deficiency worldwide, affects young women of reproductive age. This study aimed to elucidate the relationship between IDNA and mental and somatic symptoms including anger and fatigue using the Japanese version of the Cornell Medical Index Health Questionnaire (CMI-J). Data regarding demographic characteristics, anthropometry, hematological, and biochemical indices of the iron status, frequencies of selected food intakes assessed by self-administered food frequency questionnaires (FFQs), frequencies of nonspecific symptoms, and grades of neurotic tendencies assessed by CMI-J were collected from 76 young women aged 18-22 years living in the metropolitan area of Tokyo, Japan. The subjects were classified as having IDNA (hemoglobin (Hb)≥12 g/dL and serum ferritin<20 ng/mL; n=29), having iron deficiency anemia (IDA) (Hb<12 g/dL and serum ferritin<20 ng/mL; n=10), or having a normal iron status (Hb≥12 g/dL and serum ferritin≥20 ng/mL; n=36). One subject was excluded from the analyses because of Hb<12 g/dL and serum ferritin≥20 ng/mL. Fisher's protected least significant difference and the Dwass-Steel-Chritchlow-Fligner multiple comparison tests were used to compare the data of the three groups. P values<0.05 were considered significant. Sections M-R (mental complaints) were significantly higher in the IDNA subjects than in the normal subjects. No significant difference in CMI scores was found between the normal and IDA subjects. Sections I (fatigability), Q (anger), and R (tension) were significantly higher in the IDNA subjects than in the normal subjects, regardless of no significant differences between the normal and IDA subjects in those sections. Young women with IDNA demonstrated a significantly higher proportion of neurotic tendencies (grades II-IV). The intake frequency score of canned or bottled green tea fortified with vitamin C was significantly higher in the IDNA subjects than the IDA subjects. The findings suggest that IDNA may be a risk factor for anger, fatigue, and tension in women of childbearing age.