QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Mock, D. M. Search for Related Content PubMed PubMed Citation Articles by Mock, D. M.

---

Supplement

Biotin Status: Which Are Valid Indicators and How Do We Know?

Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR 72202

Although estimated average requirements for biotin have been proposed, the human requirements for biotin in specific populations and at various ages remain uncertain, in part because indicators of biotin status have not been validated. With the use of improved methods for measuring biotin and metabolites, a recent study indicated that decreased urinary excretion of biotin and bisnorbiotin is an early and sensitive indicator of biotin deficiency, but decreased serum concentration of biotin is not. Increased urinary excretion of 3-hydroxyisovaleric acid (3-HIA), a leucine metabolite that is excreted in increased quantities with deficiency of the biotin-dependent enzyme ß-methylcrotonyl-CoA carboxylase, is also an early and sensitive indicator of biotin deficiency. When these indicators were assessed longitudinally in 13 pregnant women, biotin excretion was not significantly decreased early in pregnancy but did decrease significantly from early to late pregnancy. Excretion of 3-HIA was abnormally increased in about three-fourths of the women studied in both early and late pregnancy. Thus, each indicator detected biotin deficiency late in pregnancy, but assessment of biotin status for the two indicators conflicted early in pregnancy. Preliminary results from a trial assessing response of 3-HIA excretion to biotin treatment indicate that biotin status is indeed impaired both early and late in pregnancy.

KEY WORDS: • biotin • pregnancy • teratology • birth defects • 3-hydroxyisovaleric acid

This article has been cited by other articles:

				S. C. Rathman, S. Eisenschenk, and R. J. McMahon The Abundance and Function of Biotin-Dependent Enzymes Are Reduced in Rats Chronically Administered Carbamazepine J. Nutr., November 1, 2002; 132(11): 3405 - 3410. [Abstract] [Full Text] [PDF]