Marginal biotin deficiency during normal pregnancy

Area of Science:

• Biochemistry
• Human Nutrition
• Obstetrics

Background:

• Biotin deficiency is a known teratogen in mammals.
• Increased urinary 3-hydroxyisovaleric acid (3-HIA) excretion is common in pregnancy, potentially indicating biotin deficiency.
• Pregnancy itself may affect organic acid excretion, necessitating further investigation.

Purpose of the Study:

• To test if biotin supplementation reduces 3-HIA excretion in pregnant women.
• To investigate the link between pregnancy, biotin status, and 3-HIA levels.

Main Methods:

• A randomized, placebo-controlled trial involving 26 pregnant women with elevated 3-HIA excretion.
• Participants received either 300 mcg biotin/day or a placebo for 14 days.
• Urine samples were analyzed before and after supplementation.

Main Results:

• Biotin supplementation significantly decreased 3-HIA excretion in both early and late pregnancy groups.
• In early pregnancy, 3-HIA decreased by 11.7 mmol/mol creatinine with biotin, versus an increase with placebo.
• In late pregnancy, 3-HIA decreased by 7.1 mmol/mol creatinine with biotin, versus an increase with placebo.

Conclusions:

• Elevated 3-HIA excretion in pregnancy likely reflects reduced biotin status.
• Marginal biotin deficiency may be common in the first trimester.
• This finding raises concerns about potential teratogenicity of biotin deficiency in humans.