Fasting is not required for the Heavy Metals, Environmental Toxins, or Mycotoxins tests. However, fasting for 12 hours may increase the amount of toxins excreted in urine, so consult with your ordering provider about whether they recommend you fast for 12 hours before the test. Some Vibrant America ordering providers may prefer you do a "provoked" test which requires taking a "provoking agent" (such as NAC, glutathione, DMSA, or EDTA) prior to testing to promote the release of body stores of metals so that the metals are "mobilized" (moved through the body) and excreted (released) in urine. Vibrant America does not require a provoked test, nor does Vibrant America recommend a specific provoking agent, dose, or timing of provocation before testing. Discuss with your ordering provider whether they recommend a provoked or unprovoked test, and which provoking agent, dose, and timing of provocation and urine collection they recommend for you. Please note that unprovoked test results cannot predict provoked test results as the absorption, distribution, metabolism, and excretion (release) of heavy metals in urine is highly variable in different people and is influenced by a number of physical, dietary, and environmental factors. Overall, the majority of Vibrant America ordering providers order unprovoked testing. Avoid foods high in iodine (seafood, dairy, seaweed) and selenium (Brazil nuts) as they have a strong binding affinity for heavy metals (they act like "heavy metal magnets"). Consuming these foods prior to the Heavy Metals test may cause falsely lowered results. For best test performance, collect the first morning urine upon awakening, prior to eating or drinking.