Joanna Fiddler

Assistant Professor
Food, Nutrition, and Packaging Sciences Department

Office: 215 Poole Agricultural Center
Phone: 864-656-3397
Personal Website:


 Educational Background

Ph.D. Nutritional Sciences
Oklahoma State University

M.S. Health and Human Performance
Oklahoma State University

B.S. Nutritional Sciences
Oklahoma State University

 Courses Taught

FDSC 4500 - Creative Inquiry
NUTR 8030 - Advanced Human Nutrition


Dr. Joanna Fiddler is an Assistant Professor in the Department of Food, Nutrition & Packaging Sciences at Clemson University. She earned her Bachelor of Science and Master of Science degrees in Nutritional Sciences and Health & Human Performance (exercise physiology concentration) before pursuing a PhD in Nutritional Sciences investigating iron metabolism at Oklahoma State University. She went on to study the role of B vitamin-gene interactions in mitochondrial de novo thymidylate biosynthesis and the effect of moderate iron deficiency on metabolic pathways that influence work capacity during her postdoctoral training at Cornell University in the labs of Dr. Martha Field and Professor Jere Haas. She joined the faculty at Clemson in 2023. Her work focuses on micronutrient nutrition and metabolism and studying their integration in health and disease.

 Research Interests


Walsh, DJ, Bernard, DJ, Fiddler JL, Pangilinan F, Esposito M, Harold D, Field MS, Parle-McDermott A, Brody LC. Vitamin B12 status and folic acid supplementation influence mitochondrial heteroplasmy levels in mice as they age. BioRxiv, June 2023. doi:

Fiddler JL, Blum JE, Castillo LF, Thalacker-Mercer AE, Field MS. Impairments in SHMT2 expression or cellular folate availability reduce oxidative phosphorylation and pyruvate kinase activity. Genes & Nutrition. 2023 Mar; 18(1):5.

Fiddler JL, McBurney MI, Haas JD. Using Capillary Whole Blood to Quantitatively Measure Ferritin: A Validation Trial of a Point-of-Care System. Nutrients. 2023 Mar 7;15(6):1305.

Heyden KE, Fiddler JL, Xiu Y, Malysheva OV, Handzlik MK, Phinney WN, Stiles L, Stabler SS, Metallo C, Caudill MA, Field MS. Reduced methionine synthase (Mtr) expression creates a functional vitamin B12 deficiency that leads to uracil accumulation in mouse mitochondrial DNA. PNAS Nexus. 2023 Mar 27:pgad105.

Fiddler JL, Clarke SL. Evaluation of candidate reference genes for quantitative real-time PCR analysis in a male rat model of dietary iron deficiency. Genes & Nutrition. 2021 Dec;16:1-3.

Fiddler JL, Xiu Y, Blum JE, Lamarre SG, Phinney WN, Stabler SP, Brosnan ME, Brosnan JT, Thalacker-Mercer AE, Field MS. Reduced Shmt2 expression impairs mitochondrial folate accumulation and respiration and leads to uracil accumulation in mouse mitochondrial DNA. The Journal of Nutrition. 2021 Oct 1;151(10):2882-93.

Fiddler R, Fiddler J, Ashton N, Lind E. The Effects of Beetroot Juice Supplementation on Oxygen Cost of Vigorous Intensity Aerobic Exercise in Trained Endurance Athletes. Journal of Exercise Physiology Online. 2018 Dec 1.

Bogale A, Clarke SL, Fiddler J, Hambidge KM, Stoecker BJ. Zinc supplementation in a randomized controlled trial decreased ZIP4 and ZIP8 mRNA abundance in peripheral blood mononuclear cells of adult women. Nutrition and metabolic insights. 2015 Jan;8:NMI-S23233.

Jacobson BH, Smith DB, Warren AJ, Glass RG, Kline C, Fedick JL, Stemm J. Assessment of the effectiveness of a sublingual, ergogenic spray on muscle strength and power. The Journal of Strength & Conditioning Research. 2009 Nov 1;23(8):2326-30.


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Research from ASN Journals