Estimates of mineral intakes using food composition tables vs measures by inductively-coupled plasma mass spectrometry: Part 1. calcium, phosphorus and iron.

OBJECTIVES

To examine the accuracy of food composition table (FCT)-based estimation of dietary nutrient element intake in reference to the instrumental measurement by inductively-coupled plasma mass spectrometry (ICP-MS).

DESIGN

Cross-sectional study.

SETTING

Communities.

SUBJECTS

884 adult non-smoking women in 23 study sites in 6 areas in Asia (i.e. China (Mainland), China (Taiwan), Korea, Japan, Malaysia and the Philippines.

METHODS

24-hour food duplicate samples foods offered by the women were subjected (1) to the estimation of daily dietary intake of calcium (Ca), phosphorus (P) and iron (Fe), using 6 types of national FCTs one for each area, and (2) to ICP-MS analysis for the measurement of the same elements.

RESULTS

Comparison of the estimated values (E) with corresponding measured values (M) in terms of the mean (E)/(M) ratio for each area showed that the ratio was various among the 6 areas studied. Ca showed smallest deviation (69 to 165%) from the agreement (100%), which was followed by P (113 to 306%), whereas Fe showed the largest deviation (124 to 368%).

CONCLUSIONS

Caution should be exercised in using FCTs for estimation of dietary Fe intake. The wide variation was not due to the use of the FCT established for each area, because the inter-study site variation within one area was as large as the inter-area variation.