1Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital Research Institute, Little Rock, AR 72202-3591, USA.
This study explores how to measure biotin levels in the human body. Researchers looked at biotin concentrations in blood and urine, as well as enzyme activity in lymphocytes. They found that urinary biotin and bisnorbiotin levels are good indicators of biotin status. Lymphocyte carboxylase activity and 3-hydroxyisovaleric acid excretion also reflect biotin deficiency. The study supports a daily intake of 30 microg of biotin for adults. Biotin absorption is nearly complete in humans. Certain conditions like pregnancy and anticonvulsant therapy may increase biotin needs.
You might also read
Articles linked to this work by shared authors, journal, and citation graph.
Area of Science:
Background:
Biotin metabolism remains poorly understood in terms of daily turnover and physiological thresholds. While prior research has established biotin's role in carboxylase enzyme activity, uncertainty persists about reliable biomarkers for deficiency. Existing knowledge highlights biotin's involvement in fatty acid synthesis and amino acid metabolism. However, no consensus exists on optimal biomarkers for marginal deficiency. Recent studies have proposed urinary and enzymatic indicators as potential tools. These findings suggest a need for updated dietary guidelines. Current recommendations lack precision due to variability in absorption and excretion. This gap motivates the search for more accurate diagnostic markers.
Purpose Of The Study:
The goal is to identify reliable biomarkers for marginal biotin deficiency. Researchers aim to refine estimates of daily biotin requirements. They focus on biotin concentrations in body fluids as a potential indicator. Metabolite levels and enzyme activities are also under scrutiny. The study evaluates urinary excretion patterns of specific organic acids. These markers could improve diagnostic accuracy for biotin status. The findings may inform revised dietary guidelines for biotin intake. This approach addresses limitations in current assessment methods.
The authors propose urinary biotin and bisnorbiotin levels as reliable indicators. Lymphocyte carboxylase activity and 3-hydroxyisovaleric acid excretion are also useful.
The study supports a daily intake of 30 microg (123 nmoles) of biotin for adults.
Carboxylase activity in lymphocytes decreases with marginal biotin deficiency. This makes it a sensitive biomarker for assessing biotin status.
Elevated urinary excretion of this acid is a marker of reduced carboxylase activity. It indicates marginal biotin deficiency.
Main Methods:
The study analyzed biotin concentrations in blood and urine samples. Researchers measured bisnorbiotin levels as a metabolite indicator. Lymphocyte carboxylase activities were assessed using enzymatic assays. Urinary excretion of 3-hydroxyisovaleric acid was quantified. These metrics were compared across populations with varying biotin intake. The researchers used spectrophotometric techniques for enzyme activity. Urine samples were collected over 24-hour periods. These methods allowed precise tracking of biotin turnover and deficiency markers.
Main Results:
Urinary biotin excretion averaged 30 microg per day in adults. Biotin absorption rates were found to be nearly complete in human trials. Lymphocyte carboxylase activity decreased with marginal deficiency. Urinary 3-hydroxyisovaleric acid increased under deficiency conditions. Bisnorbiotin levels correlated strongly with biotin status. These findings suggest a 30 microg/day intake is adequate for most adults. Biotin deficiency markers were detectable at lower intake levels. The results support revised dietary guidelines for biotin.
Conclusions:
The authors propose that urinary biotin and bisnorbiotin levels are reliable indicators. They suggest that carboxylase activity in lymphocytes reflects biotin status. Urinary 3-hydroxyisovaleric acid excretion is a sensitive marker of deficiency. These findings support the current 30 microg/day intake recommendation. The study confirms that biotin absorption is nearly complete in humans. Pregnancy and lactation may increase biotin requirements. Anticonvulsant therapy and lipoic acid supplementation may alter biotin needs. The authors emphasize the need for further research on these conditions.
The study found that humans absorb biotin nearly completely. This supports the 30 microg/day intake recommendation.
Pregnancy, lactation, anticonvulsant therapy, and lipoic acid supplementation may increase biotin needs.