Assessment of the prevalence of inadequate iron intakes in premenopausal females based on the reference values of the European Food Safety Authority using cross-sectional food consumption data

Am J Clin Nutr. 2024 May 4:S0002-9165(24)00459-3. doi: 10.1016/j.ajcnut.2024.04.033. Online ahead of print.

Abstract

Background: The iron intake requirement distribution for premenopausal females is not symmetric, which invalidates the estimated average requirement (EAR) cut-point approach for assessing the prevalence of iron inadequacy. Therefore, Beaton's Full probability approach (PA) must be used. Although the PA requires information on the entire iron intake requirement distribution, the European Food Safety Authority (EFSA) only provided the EAR (50th percentile), 90th, 95th (population reference intake), and 97.5th percentiles.

Objectives: This study aimed to reliably estimate the prevalence of iron inadequacy in premenopausal females using the PA, based on the intake requirements established by EFSA, and compare the results with those obtained from the EAR cut-point method.

Methods: Habitual iron intakes were calculated using the statistical program to assess dietary exposure with data from 484 females (20-45 y) from the Dutch National Food Consumption Survey 2012-2016. Iron requirements of EFSA (including additionally obtained information) were applied. Results from the PA were compared to results obtained with the EAR cut-point method. Sensitivity analyses examined the impact of lower iron intake distributions on differences in estimated inadequate intakes between PA and EAR cut-point methods.

Results: A 2-fold higher prevalence of iron inadequacy among Dutch premenopausal females was observed when employing the PA compared to the EAR cut-point method, using EFSA's reference values. Sensitivity analysis showed that the EAR cut-point method could also result in large overestimations for populations with lower intake distributions.

Conclusions: This study provided an example of using the PA method by using additionally derived information on the full requirement distribution underlying EFSA's reference values. Results showed once more the unsuitability of the EAR cut-point method to calculate the prevalence of iron inadequacy in premenopausal females. Hence, we recommend that institutions deriving dietary reference values provide all the information needed to use the correct method to determine inadequate intakes in the population.

Keywords: Beaton’s full probability approach; EAR cut-point method; EFSA; IOM; SPADE; habitual intake; iron; premenopausal females.