Research
Macro partitioning
Urinary nitrogen is a valid short-term biomarker for total protein intake, though it requires multiple 24-hour urine samples to accurately establish protein status and may underestimate high intake while overestimating low intake.
To accurately assess protein intake using urinary nitrogen, collect multiple 24-hour urine samples rather than relying on a single sample, as this significantly improves accuracy.
GoodQualifiesHIGH confidence
Urinary nitrogen is a valid method of assessing total protein intake... It is suggested that multiple 24-hour urine samples are needed to fully establish protein status
Why this rating
High correlation (0.99) with feeding studies, but requires multiple samples for accuracy.
Source
Dietary biomarkers: advances, limitations and future directions
Valisa E. Hedrick et al. · Nutrition Journal · 2012
DOI 10.1186/1475-2891-11-109
narrative_reviewCited 261×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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