Estimates of mineral intakes using food composition tables vs measures by inductively-coupled plasma mass spectrometry: Part 2: sodium, potassium, magnesium, copper and zinc

Abstract

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), as an extension of the first part of this study.

Design: Cross-sectional study.

Setting: Communities.

Subjects: 782 adult non-smoking women in 21 sites in 4 areas [China (Mainland), Japan, Korea and Malaysia in Asia.

Methods: 24-h food duplicate samples offered by the women were subjected 1. to the estimation (E) of daily element intake taking advantage of national food composition tables (FCTs) and 2. to the measurement (M) by inductively-coupled plasma mass spectrometry (ICP-MS). The two sets of the results were compared in terms of the (E)/(M) ratio. Because of the limited availability of the element database in the FCTs, the comparison on Na and K was possible in the 4 areas, whereas that of Mg, Cu and Zn was only in two areas of China (Mainland) and Japan.

Results: The (E)/(M) ratio was in a relatively narrow range of 75 to 114% in case of Na, and 91 to 120% for K (with one exception of 201% for K in Malaysia). Correlation coefficients between (E) and (M) were statistically significant for both Na and K in the 4 areas. In cases of Mg, Cu and Zn, agreements were generally poor, and the (E)/(M) ratio was close to 100% only in the cases of Cu and Zn in Japan.

Conclusions: In overall evaluation combining the results on Ca, P and Fe in the preceding report with the results in the present report on Na, K, Mg, Cu and Zn, FCT-based estimation generally did not agree with the measure by ICP-MS. The disagreement did not allow precise FCTs-based estimation of dietary intakes of these nutrient elements, possibly except for Na.

Sponsorship: Dai-ichi Mutual Life Insurance, Japan; Iijima Memorial Foundation for the Promotion of Food Science and Technology, Japan; The Ministry of Education, Science, Sports and Culture and the Ministry of Health and Welfare, the Government of Japan.