Sodium benzoate glycine "N"-acyltransferase into hippuric acid. In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate may form benzene. When tested by the FDA, most beverages that contained both ascorbic acid and benzoate had benzene levels that were below those considered dangerous for consumption by the World Health Organization (5 ppb). Most of the beverages that tested higher have been reformulated and subsequently tested below the safety limit. Heat, light and shelf life can increase the rate at which benzene is formed. Research published in 2007 for the UK's Food Standards Agency (FSA) suggests that certain artificial colors,
Vitamin B6 4-pyridoxic acid. Several studies have shown that 4-pyridoxic acid is undetectable in the urine of vitamin B-deficient subjects, making it a useful clinical marker to assess the vitamin B status of an individual. Other products of vitamin B metabolism excreted in the urine when high doses of the vitamin have been given include pyridoxal, pyridoxamine, and pyridoxine and their phosphates. A small amount of vitamin B is also excreted in the feces. The classic clinical syndrome for vitamin B deficiency is a seborrhoeic dermatitis-like eruption, atrophic glossitis with ulceration, angular cheilitis, conjunctivitis, intertrigo, and neurologic symptoms of somnolence, confusion, and