In Reply: Drs Watts and Mercola and Drs Kaminski and Glade acknowledge that there is variability among laboratories performing hair mineral analysis. However, they disagree with our conclusion that hair mineral testing is unreliable.
Watts and Mercola suggest that including an uncertified and illegally operating laboratory (Laboratory B) unfairly introduced greater variability into the results. Laboratory selection was based on volume of analyses and available hair as shown in Table 1 of our article. Steindel and Howanitz,1 in their accompanying Editorial, calculated a mean coefficient of variation (coefficient of variation = SD/mean) across laboratories of 103.5%. Excluding Laboratory B, and restricting the analysis to the 19 elements reported by all laboratories, the mean coefficient of variation for the 5 remaining laboratories is 68%, still above the cited normal limits of 10% for common analytes and 15% to 50% for more exotic ones. The uncertified laboratory was selected prior to learning that it was falsely advertising certification. There is no Clinical Laboratory Improvement Act certification for hair analysis, so the certification advertised by all the laboratories must be for some other application.
Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more
Subscribe for full-text access to content from 1998 forward and a host of useful features
Activate your current subscription (AMA members and current subscribers)
Purchase Online Access to this article for 24 hours
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and
Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early
dhildhood mortality and growth failure data and their association with maternal
Thank you for submitting a comment on this article. It will be reviewed by JAMA editors. You will be notified when your comment has been published. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest*
Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Web of Science® Times Cited: 1
Customize your page view by dragging & repositioning the boxes below.
More Listings atJAMACareerCenter.com >
and access these and other features:
Enter your username and email address. We'll send you a link to reset your password.
Enter your username and email address. We'll send instructions on how to reset your password to the email address we have on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.