Self-report of 24-hour urine completeness compared to PABA recovery does not bias estimates of dietary salt intake in the UK.
The British journal of nutrition 2026
Jones KS, Collins D, Meadows SR, Parkington DA, Koulman A, Page P
DOI : 10.1017/S0007114525106132
PubMed ID : 41491972
PMCID :
Abstract
The measurement of sodium excretion in 24-hour urine samples is the recommended method to assess dietary salt intake to monitor salt-related public health policies. Ensuring complete collection of 24-h urine samples is important for the accurate assessment of salt intake. We compare the use of the objective biomarker, recovery of para-aminobenzoic acid (PABA), to self-reported 24-h urine completeness. Data collected from 868 men and women aged 19 to 64 years from the England Sodium Survey 2018/19 (part of the UK National Diet and Nutrition Survey (NDNS)) were used to compare self-reported 24-h urine completeness based on collection duration of 23-25 h, no missed urine collections/voids, and a minimum urine volume of > 0.4 L against completeness based on the urinary recovery of oral doses of PABA.Two-thirds (69%; 561/812) of participants who adhered to the PABA protocol provided a complete 24-h urine collection. Assessed by self-report, 71% (619/868) of participants provided a complete 24-h urine collection. Sodium excretion was (geometric mean (interquartile range)) 127 (97, 170) mmol/24 h with PABA and 126 (97, 169) mmol/24 h by self-report; salt intake was 7.40 (5.65, 9.94) g/d and 7.38 (4.53, 8.83) g/d, respectively. The proportion of participants above the UK recommended salt intake of 6 g/d was 70% by both PABA and self-report.This study shows that the use of self-report of 24-h urine collection completeness provides an assessment of sodium excretion and dietary salt intake with the same accuracy as when PABA recovery is used to assess completeness.