(P02-027-25) Iron Deficiency Rates Among US Females 1-18y: National Health and Nutrition Examination Survey 2001-March 2020

Objectives: Iron is an important nutrient for growth and development. This National Health and Nutrition Examination Survey (NHANES) analysis evaluated whether females 1-18y who used iron supplements had better iron status compared to non-users.

Methods: This was a secondary analysis of individuals 1-18y who participated in the NHANES 2001-March 2020. Participants were excluded if they were pregnant or did not provide at least one reliable dietary recall. We compared Serum Ferritin, Hematocrit, and Hemoglobin among Females 1-18y and stratified by iron-containing supplement use. Iron supplement use was obtained from responses to the 30-day supplement use questionnaire. Serum ferritin was adjusted for inflammation status using the BRINDA adjustment method. Iron deficiency was considered as serum ferritin < 15 µg/L. Appropriate sampling adjustments and sample weights were applied to all analyses. Differences between iron supplement users and non-users were estimated using independent samples t-tests. Trends across age groups were assessed using linear models. P-values < 0.05 were considered statistically significant.

Results: A total of 15,882 females 1-18 y were included for analysis. Iron supplement use varied across age groups from 11.5% among 1-3y, 13.7% among 4-8y, 10.8% among 9-13y and 11.7% among 14-18y. Mean[SE] iron deficiency rates increased with age in those females using iron supplements (1-3y: 1.8[0.9]%, 4-8y: 2.4[1.1]%, 9-13y: 10.6[3.3]%, and 14-18y: 31.2[3.8]%; p-trend < 0.001). Among those who did not use an iron supplement, deficiency rates also increased with age with the exception of 4-8y vs. 1-3y (1-3y: 14.2[1.4]%, 4-8y: 5.8[1.0]%, 9-13y: 16.0[1.5]%, and 14-18y: 29.7[1.4]%; p-trend < 0.001). Iron supplement users reported significantly lower rates of iron deficiency compared to non-iron supplement users among 1-3y (p < 0.001) and among 4-8y (p=0.017). There were no significant differences in low hematocrit or hemoglobin between iron supplement users and non-users.

Conclusions: Females 1-8y who did report supplement use were less likely to have iron deficiency compared to non-users, yet no differences were observed for 9-18y. More work is needed to understand the determinants of iron status in this population and strategies to improve status given the low supplementation rates.

Funding Sources: Mead Johnson Nutrition