Effect of vegetarian diets on zinc status: a systematic review and meta‐analysis of studies in humans (1043.1)

Abstract

Plant‐based diets contain more folate, fibre, and phytochemicals than omnivorous diets, however some micronutrients, especially zinc, are poorly bioavailable. The findings of studies exploring the zinc intake and zinc status in populations that habitually consume vegetarian diets are inconsistent. This study aims to investigate the effects of plant‐based diets on dietary zinc intake and status in humans using systematic review and meta‐analysis techniques. Thirty‐four studies were included in the systematic review. Of these, 26 studies (reporting 48 comparisons) compared males and/or females consuming vegetarian with non‐vegetarian groups, and were included in meta‐analyses. Dietary zinc intakes and serum zinc concentrations were significantly lower (‐0.88 ± 0.15 mg/d, and ‐0.93 ± 0.27 μmol/L, P=0.001, respectively; mean ± SE) in populations that followed habitual vegetarian diets compared to non‐vegetarians. Secondary analyses showed greater impact of vegetarian diets on the zinc intake and status of females, vegetarians from developing countries, and vegans. Populations that habitually consume vegetarian diets have low zinc intakes and status. Dietary practices that increase zinc bioavailability, the consumption of foods fortified with zinc, or low dose supplementation are strategies that should be considered for improving the zinc status of vegetarians.