Natural occurring chemicals found in foods (e.g., folate, choline) and beverages (e.g., polyphenols, benzoate) have been associated with both positive and negative health responses. Perturbations in endogenous metabolism have been associated with many prescription and over the counter medications, as well as illicit drugs. Metabolites of many environmentally relevant chemicals are also detected (including phthalates, pesticides, polycyclic aromatic hydrocarbons, parabens, brominated flame r...
