About the Authors

Katherine M. Phillips

kmpvpi@vt.edu

Affiliation Biochemistry Department, Virginia Tech, Blacksburg, Virginia, United States of America

Ronald L. Horst

Affiliation Heartland Assays, Inc., Ames, Iowa, United States of America

Nicholas J. Koszewski

Affiliation Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America

Ryan R. Simon

Affiliation Cantox Health Sciences International, Mississauga, Ontario, Canada

Competing Interests

Katherine Phillips is a Senior Research Scientist at Virginia Tech and has received funding from the United States Department of Agriculture for this work. She has also received funding from the Mushroom Council but the present study was initiated independently and not commissioned or funded by the Mushroom Council. Ronald Horst is Owner/Director of Heartland Assays LLC. Heartland Assays provides analytical and consulting services to many Academic and Commercial institutions regarding interpreting and application Vitamin D assays. These activities will not interfere with the objective presentation and sharing of information presented in the PLoS ONE manuscript. Nick Koszewski is an employee of Iowa State University, College of Veterinary Medicine and has on occasion acted as a consultant in the identification of vitamin D compounds. His activities will not interfere with the objective presentation and sharing of data presented in the PLoS ONE manuscript. Ryan Simon is an employee of Intertek Cantox a scientific and regulatory consulting company, Intertek Cantox has provided consulting services to the U.S. mushroom industry over the past three years. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: KMP RLH. Performed the experiments: RLH NJK. Analyzed the data: KMP RLH RRS. Contributed reagents/materials/analysis tools: KMP RLH NJK. Wrote the paper: KMP RRS RLH.