From the Research
The recommended over-the-counter (OTC) dose of biotin is 30 micrograms (mcg) per day for adults, which is sufficient for most healthy individuals to maintain normal biotin levels. For general health maintenance, 30 mcg daily is adequate as this meets the recommended daily allowance. However, some people take higher supplemental doses of 2,500 to 5,000 mcg (2.5 to 5 mg) daily for hair, skin, and nail health, though scientific evidence supporting these higher doses for cosmetic benefits is limited, as noted in a review of biotin for hair loss 1. Biotin is a water-soluble B vitamin (B7) that helps convert food into energy and plays an important role in the health of hair, skin, and nails. Since it's water-soluble, excess biotin is typically excreted in urine. It's also worth noting that higher intake of biotin has been associated with a lower odds of depression, anxiety, and stress symptoms, as found in a cross-sectional study 2.
Some key points to consider when taking biotin supplements include:
- Biotin deficiency can cause symptoms such as seizures, hypotonia, ataxia, dermatitis, hair loss, mental retardation, ketolactic acidosis, and organic aciduria, as discussed in a review of biotin and biotinidase deficiency 3.
- The intestine plays a crucial role in biotin absorption, and the sodium-dependent multivitamin transporter (SMVT) is the main biotin uptake system in human intestinal epithelial cells, as studied in cell and molecular aspects of human intestinal biotin absorption 4.
- Very high biotin doses can interfere with certain laboratory tests, particularly thyroid function and cardiac troponin tests, so it's essential to inform your healthcare provider about biotin supplementation before undergoing any blood tests.
- Trends in daily use of biotin supplements among US adults have been characterized, showing an increase in use over the years, as reported in a pharmacoepidemiology study 5.