Biotin Deficiency in Pregnancy

Biotin Deficiency in Pregnancy


Most people are not deficient in biotin. However, that said, biotin deficiency is difficult to measure. Deficiencies known to exist in a variety of situations including pregnancy, inflammatory bowel disease, Advanced age, oral antibiotics, alcoholism and certain medications (like isotretinoin, valproic acid and carbamazepine). Unlike many blood tests for testing “deficiencies”, there is no simple “biotin” blood test.

One way to determine if someone is biotin deficient or not is to evaluate for increased urinary excretion of 3-hydroxyisovaleric acid (3HIA), which likely reflects decreased activity of the biotin-dependent enzyme beta-methylcrotonyl-CoA carboxylase. A second way is to search for decreased activity of the biotin-dependent enzyme propionyl-CoA carboxylase (PCC) in peripheral blood lymphocytes.

A 2009 study by Mock and colleagues provided evidence that biotin deficiency may actually be quite common during pregnancy. In their pilot study, activity of PCC in peripheral blood lymphocytes (as a measure of biotin deficiency) was decreased in 18 of 22 (81%) pregnant women.

These studies are interesting. While they draw attention to the issue of biotin deficiency in pregnancy, it also draws attention to whether such deficiency impacts the hair during or after pregnancy. This is not known at present but deserves further study. Biotin deficiency may be more common during pregnancy than most realize.


Marginal biotin deficiency is common in normal human pregnancy and is highly teratogenic in mice. Mock DM. J Nutr. 2009.

Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887

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