7951
document
Marginal biotin deficiency during normal pregnancy . BACKGROUND Biotin deficiency is teratogenic in several mammalian species . Approximately 50 % of pregnant women have an abnormally increased urinary excretion of 3-hydroxyisovaleric acid ( 3-HIA ) , which probably reflects decreased activity of the biotin-dependent enzyme methylcrotonyl-CoA carboxylase . However , increased 3-HIA excretion could result from pregnancy per se ( eg , from an effect of pregnancy on renal handling of organic acids ) . OBJECTIVE We tested the hypothesis that biotin supplementation significantly decreases 3-HIA excretion in pregnant women with abnormally increased 3-HIA excretion . DESIGN Twenty-six pregnant women with increased 3-HIA excretion were studied in a randomized , placebo-controlled trial ; 10 women were studied during early pregnancy ( 6-17 wk gestation ) and 16 women during late pregnancy ( 21-37 wk gestation ) . Urine samples were collected before and after 14 d of supplementation with 300 microg ( 1.2 micromol ) biotin/d or placebo . RESULTS In the early-pregnancy group , 3-HIA excretion decreased ( P < 0.006 ) by 11.7 +/- 3.6 mmol/mol creatinine ( mean +/- SEM ) in the 5 women who received biotin supplements , whereas 3-HIA excretion increased by 1.6 +/- 0.6 mmol/mol creatinine in the 5 women who received placebo . In the late-pregnancy group , 3-HIA excretion decreased ( P < 0.002 ) by 7.1 +/- 1.2 mmol/mol creatinine in the 8 women who received biotin supplements , whereas 3-HIA excretion increased by 0.9 +/- 1.8 mmol/mol creatinine in the 8 women who received placebo . CONCLUSIONS This study provides evidence that the increased excretion of 3-HIA seen frequently in normal pregnancy reflects reduced biotin status . The conclusion that marginal biotin deficiency occurs frequently in the first trimester further raises concern about potential human teratogenicity .
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Intervention_Control
placebo-controlled
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Intervention_Pharmacological
300 microg ( 1.2 micromol ) biotin/d
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Intervention_Control
placebo
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Outcome_Physical
3-hydroxyisovaleric acid ( 3-HIA )
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Outcome_Physical
Urine samples
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Outcome_Physical
3-HIA excretion
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Outcome_Physical
3-HIA excretion
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Outcome_Physical
3-HIA excretion
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Outcome_Physical
3-HIA excretion
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Outcome_Physical
excretion of 3-HIA
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Outcome_Physical
biotin status .
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Participant_Condition
normal pregnancy
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Participant_Condition
pregnant
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Participant_Sex
women
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Participant_Condition
pregnant
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Participant_Sex
women
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Participant_Condition
increased 3-HIA excretion
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Participant_Sample-size
Twenty-six
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Participant_Condition
pregnant
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Participant_Sex
women
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Participant_Condition
increased 3-HIA excretion