Editing Biotin (section)

===Factors that affect biotin requirements===
Chronic alcohol use is associated with a significant reduction in plasma biotin.<ref name=Said2011>{{cite journal |vauthors=Said HM |title=Intestinal absorption of water-soluble vitamins in health and disease |journal=Biochem J |volume=437 |issue=3 |pages=357–72 |date=August 2011 |pmid=21749321 |pmc=4049159 |doi=10.1042/BJ20110326 |url=}}</ref> Intestinal biotin uptake also appears to be sensitive to the effect of the anti-[[epilepsy]] drugs [[carbamazepine]] and [[primidone]].<ref name=Said2011 /> Relatively low levels of biotin have also been reported in the urine or plasma of patients who have had a partial [[gastrectomy]] or have other causes of [[achlorhydria]], as well as burn patients, elderly individuals, and athletes.<ref name=Combs>{{cite book| author = Combs GF | title= The Vitamins: Fundamental Aspects in Nutrition and Health | year= 2008| publisher= San Diego: Elsevier, Inc| isbn = 978-0-12-183493-7}}</ref> Pregnancy and [[lactation]] may be associated with an increased demand for biotin. In pregnancy, this may be due to a possible acceleration of biotin [[catabolism]], whereas, in lactation, the higher demand has yet to be elucidated. Recent studies have shown marginal biotin deficiency can be present in [[human gestation]], as evidenced by increased urinary excretion of [[beta-Hydroxy beta-methylbutyric acid|3-hydroxyisovaleric acid]], decreased urinary excretion of biotin and bisnorbiotin, and decreased plasma concentration of biotin.<ref name=PKIN2020Biotin />