Question: Is a high value of arsenic a concern?   Yes, arsenic is a toxin. You probably don’t want a lot of it, if it's just a little high it might not cause terrible damage.   I would look at methylation if I saw high arsenic, because methylation is needed to get rid of arsenic.   Oh actually I should add that methylation supplements have been shown to help arsenic detoxification in areas of the world where arsenic was a serious concern.   This Q&A can also be found as part of a much longer episode, here: https://chrismasterjohnphd.com/podcast/2019/02/24/ask-anything-nutrition-feb-17-2019/   If you would like to be part of the next live Ask Me Anything About Nutrition, sign up for the CMJ Masterpass, which includes access to these live Zoom sessions, premium features on all my content, and hundreds of dollars of exclusive discounts. You can sign up with a 10% lifetime discount here: https://chrismasterjohnphd.com/q&a