Biotin: Daily Intake Requirements, Sources, and Deficiency Effects

Biotin, a water-soluble vitamin crucial for lipid metabolism, amino acid breakdown, and other cellular processes, has specific daily intake requirements: 0.7 μg/kg for infants, 8–20 μg/day for children depending on age, 30 μg/day for adults, and 35 μg/day during lactation. Intestinal bacteria typically provide sufficient biotin, with foods like soybeans, liver, cauliflower, mushrooms, bean sprouts, and eggs contributing significantly to adult needs. Deficiency in biotin can lead to a range of health issues, including impaired glucose tolerance, mental dysfunction, muscle pain, sensory disturbances, appetite loss, skin conditions, hair loss, weakened immune function, and potential teratogenic effects. Biotin deficiency can be exacerbated by a lack of pantothenic acid. Biotin is absorbed in the small intestine through a high-affinity, low-capacity sodium/multivitamin cotransporter and its uptake is regulated by protein kinase C and calcium/calmodulin signaling, which adjusts absorption based on intake levels.