Biotin (Vitamin B7)

Biotin is a cofactor for five carboxylase enzymes involved in fatty acid synthesis, gluconeogenesis, and amino acid catabolism. It supports the conversion of pyruvate to oxaloacetate (a key step in energy metabolism) and is essential for the synthesis of keratin — the structural protein of hair and nails. Biotin also supports glucose metabolism by activating glucokinase in the pancreas.

Included at therapeutic doses for patients experiencing hair thinning, brittle nails, and fatigue — all common symptoms of biotin deficiency, which is more prevalent than commonly recognized, especially in individuals with gut dysbiosis (gut bacteria produce biotin, so dysbiosis reduces endogenous production).

Multiple studies confirm biotin's role in hair and nail health. A 2015 study showed significant improvement in hair growth in women with self-perceived thinning hair after biotin supplementation. Biotin deficiency is associated with fatigue, depression, and peripheral neuropathy.

High-dose biotin (5,000–10,000mcg) can interfere with thyroid lab tests (TSH, T3, T4) — stop supplementation 48–72 hours before thyroid blood draws.