Figure 2.

Analysis of zinc biomarkers at baseline. (A) Total zinc concentrations in the serum of omnivores (WD, n = 40), flexitarians (Flex, n = 47), vegetarians (VG, n = 45), and vegans (VN, n = 40) were determined using total reflection X-ray fluorescence spectroscopy (TXRF). The dashed lines indicate the reference range of zinc in serum, with the numbers below the violin plots representing the percentage of subjects below this threshold. (B) Free serum zinc levels were quantified by a fluorometric method using the low-molecular-weight fluorescent sensor Zinpyr-1. (C) Daily zinc intakes were calculated from baseline dietary records conducted over 5 days (WD n = 37, Flex n = 46, VG n = 39 and VN n = 38). (D) Phytate Diet Scores of baseline dietary records were calculated based on the questionnaire of Trame et al. [24]. The results are shown as median with 25- and 75-quartile range (indicated as dotted lines). Diet groups that do not share indices (a–d) differ significantly (Kruskal–Wallis test followed by Benjamini–Hochberg correction (p < 0.05)).