Oral manganese intake estimated with dietary records and with direct chemical analysis

The estimation of the daily oral intake of manganese (Mn) can vary significantly with the method used. This study aims to compare two different approaches: the use of dietary records along with tables of the Mn contents of different foods and the parallel collection of identical aliquots which are analyzed for Mn. Dietary samples and information were collected during a 3-day dietary assessment with five participants. The average daily oral intake of Mn estimated from the dietary records and tables of Mn contents was 3.52 mg/day (S.D. = 1.9), which corresponds to an exposure dose (ED) of 50.27 microg/kg body wt./day (S.D. = 26.2). With a parallel collection of identical aliquots and chemical analysis, the average intake was 2.88 mg/day (S.D. = 0.64) for an ED of 41.18 microg/kg body wt./day (S.D. = 8.9). Thus, the use of tables gives an estimated oral dose 22% higher than the more accurate direct chemical analysis.