Spot urine sampling yields reliable measurements for urine caffeine and caffeine metabolites over short-to-intermediate timeframes in a regional cohort of 50 United States adults
Overall, 1-2 spot urine samples were sufficient to obtain a reliable concentration estimate (ICC ≥ 0.80) for caffeine and most caffeine metabolites during 24-h or 1-wk sampling timeframes with appropriate urine flow adjustment, with 2-3 spot urine samples being sufficient for sampling over 6 wk.
Authors
- Marsha K. Morgan
- P. Simon
- Michael E. Rybak (ORCID: https://orcid.org/0000-0003-1650-8581)
- Maya Sternberg (ORCID: https://orcid.org/0000-0001-9762-0350)
Institutions
- Environmental Protection Agency (US)
- Research Triangle Park Foundation (US)
- National Center for Environmental Health (US)
- Environmental Protection Agency (IE)
Publication Details
- Journal
- American Journal of Clinical Nutrition
- Published
- 2025-09-18
- DOI
- https://doi.org/10.1016/j.ajcnut.2025.09.022
- Primary Topic
- Coffee research and impacts
- Type
- article
- Field-Weighted Citation Impact
- 0.00