Objective: Evaluation of a 2-day food record (FR) for the assessment of iron, calcium and vitamin C intake.
Design: In a subsample of a large-scale epidemiological study, iron, calcium and vitamin C intake were estimated using a 2-day FR and compared to the nutrient intakes assessed by an 11-day FR (reference method).
Setting: City of Ghent, Dutch speaking part of Belgium.
Subjects: A number of 51 non-pregnant women (18-39 years).
Results: Mean iron, calcium and vitamin C intakes were not significantly different between the reference method and 2-day FR. Correlation coefficients of 0.63 (iron) and 0.76 (calcium, vitamin C) were reached. The iron intake of 95% of the individuals assessed by the 2-day FR varied between 5 mg above or below the reference intake. Over 50% of the women were correctly classified and 4% or fewer were extremely misclassified by the 2-day FR. Mean 11-day FR intakes increased progressively over the tertiles defined by the 2-day FR. The 11-day energy intake was under-reported by 28% of the women; no over-reporters were identified.
Conclusions: The 2-day FR is able to estimate mean iron, calcium and vitamin C intake and to rank individuals along the distribution of intakes.