Urinary trace element levels in vegans compared with lacto-ovo-vegetarians and omnivores

Studies assessing potential differences in trace element status among vegans, lacto-ovo-vegetarians (LOV) and omnivores (OMN) are largely lacking. In this cross-sectional study, urinary levels of twelve elements were analysed in thirty-eight vegans, thirty-seven LOV and forty OMN. After adjustment for covariates, non-creatinine-adjusted As levels were lower in LOV (-54 %) and vegans (-54 %) compared with OMN (P = 0·009). Compared with OMN, vegans (but not LOV) had lower Hg (-48 %; P = 0·028) and higher Cd levels (+42 %; P = 0·023). Other elements (Al, Co, Cu, Pb, Mo, Ni, Tl, Sn and Zn) were similar between groups. Analyses normalised to urinary creatinine confirmed lower As levels in LOV (-63 %) and vegans (-59 %; P < 0·001), but suggested similar Hg and Cd levels in OMN, LOV and vegans, higher Co in LOV (+53 %; P = 0·035) and higher Cu in vegans (+17 %; P = 0·040). Trends (non-significant after adjustment for multiple testing) were noted for Ni (LOV: +119 %), Co (vegans: +43 %) and Zn (vegans: -26 %; compared with OMN). LOV and vegans had similar urinary levels (P ≥ 0·207). Urinary creatinine levels were similar across all groups (P ≥ 0·912). Eight additional elements were not detected (Bi, Au, In, Ir, Pd and Ag) or were detected only in a few samples (Pt and Zr). Overall, LOV and vegans exhibited a lower As burden than OMN. A higher Cd and lower Hg burden in vegans were not confirmed in creatinine-adjusted analyses. Similar studies are warranted to validate results. Biomonitoring studies may benefit from considering vegetarian status, particularly for As exposure.