Why does FullWell Prenatal contain 500 mcg of biotin?Updated 7 days ago

FullWell Prenatal includes 500 mcg of biotin to support the increased metabolic demands of pregnancy, optimize fetal development, and safeguard against subclinical deficiency, which is more common than many realize, even with adequate dietary intake.

Biotin needs increase during pregnancy

Biotin is critical in energy metabolism, gene regulation, and fatty acid synthesis—functions essential to maternal health and fetal development. During pregnancy, biotin catabolism accelerates, meaning the body breaks it down more quickly. As a result, plasma biotin levels drop, and up to 50% of pregnant women show signs of functional deficiency, despite consuming the recommended daily intake (Mock, 2009; Institute of Medicine, 1998).

Citation:

1. Mock DM. Biotin: from nutrition to therapeutics. J Nutr. 2009;139(2):353–357.

2. Institute of Medicine. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. 1998.

The standard recommendation may not be sufficient

The adequate intake (AI) for biotin in pregnancy is set at just 30 mcg/day, but this is based on limited data and not necessarily reflective of optimal status. A dose of 500 mcg provides a supportive buffer to help meet individual needs, especially in women who may not absorb biotin efficiently or are taking medications that deplete it.

Several common medications and lifestyle factors deplete biotin

Women on certain medications may have increased biotin needs due to depletion. These include:

 • Anticonvulsants (e.g., carbamazepine, phenytoin)

 • Antibiotics (long-term use)

 • Isotretinoin (used for acne)

 • Valproic acid

 • Sulfonamide antibiotics

 • Chronic alcohol use and smoking

Citation:

1. Zempleni J et al. J Nutr. 2009;139(2):359–364.

2. Said HM. Biotin: biochemical, physiological and clinical aspects. Subcell Biochem. 2012;56:1–19.

No established upper limit

Although 500 mcg may seem high compared to the AI, it is well within safe limits:

 • No Tolerable Upper Intake Level (UL) has been established for biotin due to its low toxicity profile and water solubility.

 • The body excretes what it doesn’t need through urine, and absorption plateaus at high doses—so it’s not about “more is better,” but ensuring sufficiency across a wide range of needs.

Citation:

1. Institute of Medicine. DRIs, 1998. (The last time DRI’s for Biotin were updated)

2. Zempleni J. Pharmacokinetics of biotin in humans. J Nutr Biochem. 1995.