For much of the world’s population,food is the major source of exposure to arsenic.Exposure to this non-essential metalloid at relatively low levels may be linked to a wide range of adverse health effects.Thus,evaluating foods as sources of exposure to arsenic is important in assessing risk and developing strategies that protect public health.Although most emphasis has been placed on inorganic arsenic as human carcinogen and toxicant,an array of arsenic-containing species are found in plants and animals used as foods.Here,we 2evaluate the contribution of complex organic arsenicals (arsenosugars,arsenolipids,and trimethylarsonium compounds) that are found in foods and consider their origins,metabolism,and potential toxicity.Commonalities in the metabolism of arsenosugars and arsenolipids lead to the production of di-methylated arsenicals which are known to exert many toxic effects.Evaluating foods as sources of exposure to these complex organic arsenicals and understanding the formation of reactive metabolites may be critical in assessing their contribution to aggregate exposure to arsenic.