Twenty-four-hour urinary thiamine as a biomarker for the assessment of thiamine intake

Abstract

Objective: To investigate 24-h urinary thiamine as a potential biomarker for thiamine intake for use in validation studies to assess the validity of dietary intake data collected by self-reporting dietary methods. Subjects: Seven male and six female healthy participants living for 30 days in a metabolic suite under strictly controlled conditions consuming their usual diet as assessed beforehand from four consecutive 7-day food diaries kept at home. During the 30-day study, all 24-h urine specimens were collected, validated for their completeness and analysed for thiamine. Results: Thirty-day mean (7s.d.) calculated thiamine intake was 2.2270.55 mg/day. Thirty-day mean (7s.d.) urinary excretion of thiamine was 526.57193.0 mg/day (24.778.10% of intake). There was a highly significant correlation between individuals' 30-day means of thiamine intake and their mean excretion level (r ¼ 0.720; P ¼ 0.006), where 1 mg of thiamine intake predicted 268.2 mg of thiamine in urine. The correlations between intake and excretion remained significant when measurement from a single 24-h urine collection was used (r ¼ 0.56). Conclusion: Twenty-four-hour urinary thiamine can be used as a concentration biomarker for thiamine intake in dietary validation studies.

Intra- and Inter-Individual Variations of Blood and Urinary Water-Soluble Vitamins in Japanese Young Adults Consuming a Semi-Purified Diet for 7 Days

“…To our knowledge, there is only a single report to assess CVWS and CVBS in urinary excretion of water-soluble vitamins (20 (20). In the present study, CVWS in urinary thiamin obtained was lower than the reported value.…”

“…Although we did not survey vitamin C intakes of the subjects in the few days prior to the experiment, the subjects might have taken less than 100 mg/ d of vitamin C prior to the experiment, and intake of 100 mg/d of vitamin C might have improved their values. Since higher vitamin C intake also increases urinary excretion of ascorbic acid (20,21,24), increase of urinary ascorbic acid during the experiment in female subjects might have been due to higher vitamin C intake during the experiment than in the previous days.…”

“…A similar phenomenon was observed in urinary excretion of other water-soluble vitamins. Tasevska et al also investigated the inter-individual variations in percentage urinary recovery of thiamin, and their high variability implies that urinary thiamin can be used as a concentration biomarker rather than recovery and predictive biomarkers (20). The former biomarker can be used as a tool for ranking individuals according to dietary exposure, and the latter two can quantitatively reflect the balance between intake and output or predict dietary intake.…”

Urinary Water-Soluble Vitamins as Nutritional Biomarker to Estimate Their Intakes

“…However, only a single study had investigated urinary vitamin as a possible marker for intake until 2007. Individuals' 30-day means of thiamin intake are highly correlated with their mean 24-hr urine thiamin levels under strictly controlled condition, showing 24-hr urinary thiamin as a useful marker for thiamin intake under strictly controlled conditions (Tasevska et al, 2007).…”

Twenty-four-hour urinary water-soluble vitamin levels correlate with their intakes in free-living Japanese schoolchildren

“…Methods using biomarkers for assessing vitamin intakes offer an effective approach to evaluate vitamin status in individuals. Many preceding studies have investigated urinary excretion as a biomarker for vitamin intake (1)(2)(3) . We have also reported recently that 24 h urinary levels of water-soluble vitamins correlate highly with their intakes for Japanese college students in a strictly controlled environment (4,5) .…”