Biotin

BRAND NAMES

Biotin is available under various brand names, including Coenzyme R, Vitamin H, Nail-ex, and Appearex, as well as popular supplement brands such as GNC, Oziva, Carbamide Forte, and HealthKart. Additional brands and products found on the market include Bodywise, Mars by GHC, Dr. Morepen Biotin+, and Zingavita, among others.

MECHANISM OF ACTION

Biotin primarily functions as a coenzyme for five essential carboxylase enzymes that play critical roles in metabolic processes including fatty acid synthesis, gluconeogenesis, and amino acid catabolism. It facilitates these reactions by serving as a carrier of carboxyl groups (𝐶𝑂2CO2) in a series of multi-step enzymatic conversions. In addition to its coenzyme activity, research indicates that biotin also influences gene expression through mechanisms such as modifying histones, and it is involved in cell signaling and immune system regulation.

PHARMACOKINETICS:

Absorption

Biotin is primarily absorbed in the small intestine through a carrier-mediated process called the sodium-dependent multivitamin transporter (SMVT). At very high, pharmacological concentrations, absorption can also occur through passive diffusion. Distribution

Biotin is found in a wide variety of both animal- and plant-based foods, with especially high levels in organ meats, egg yolks, fish, and nuts.

Metabolism

Biotin, a B-complex vitamin, serves as a coenzyme for multiple biotin-dependent carboxylase enzymes, which are essential for catalyzing carbon dioxide transfer reactions involved in key metabolic pathways such as gluconeogenesis, fatty acid synthesis, and amino acid metabolism.

Excretion

Biotin is a water-soluble B vitamin, and its elimination is mainly carried out by the kidneys. Because the body does not store excess water-soluble vitamins, any surplus is excreted through urine. Urinary excretion of biotin includes both the unchanged biotin molecule and its metabolic breakdown products.

PHARMACODYNAMICS

Biotin’s pharmacodynamics center on its role as a crucial coenzyme for carboxylase enzymes involved in the metabolism of carbohydrates, fatty acids, and amino acids. Beyond its coenzyme functions, biotin at pharmacological doses can affect gene expression linked to glucose and lipid regulation, suggesting potential benefits in managing conditions like hyperglycemia and hyperlipidemia. Additionally, high-dose biotin has been explored as a therapeutic option for neurodegenerative diseases such as multiple sclerosis, where it may support energy production and promote myelin repair in nerve axons.

ADMINISTRATION

Biotin (vitamin B7) is most commonly taken orally as a dietary supplement, but in specific medical cases, it may also be administered intravenously. It can be taken with or without food; however, consuming it with food may help reduce the risk of stomach discomfort.

DOSAGE AND STRENGTH

The dose of this medicine varies for each person and should be taken as directed by your doctor or the label. For preventing biotin deficiency, adults and teens usually take 30 to 100 micrograms (mcg) daily. Children aged 7 to 10 take 30 mcg, ages 4 to 6 take 25 mcg, and children under 3 take 10 to 20 mcg per day. To treat a deficiency, the doctor will decide the right dose based on how severe the deficiency is.

DRUG INTERACTIONS

While some medications should never be used together, others can be combined even if there is a potential for interaction. In such cases, your doctor may adjust the dosage or take other necessary precautions. Be sure to inform your healthcare provider about any prescription or over-the-counter (OTC) medications you are currently taking.

FOOD INTERACTIONS

Certain foods can interfere with the absorption of biotin, including raw egg whites, processed foods, and high amounts of alcohol. Some raw vegetables, such as cauliflower, and even salmon may contain compounds that reduce biotin absorption, although cooking can help lessen this effect. To maximize biotin intake, it's best to eat whole, unprocessed foods and ensure items like eggs are properly cooked.

CONTRAINDICATIONS

Biotin is contraindicated in individuals with a known hypersensitivity or allergic reaction to biotin or any of its formulation ingredients. Although rare, allergic responses such as skin rash or swelling may occur. Additionally, high doses of biotin can interfere with certain laboratory tests, including thyroid function and cardiac marker assays, leading to potentially false results; therefore, patients should inform healthcare providers about biotin use before undergoing testing.

SIDE EFFECTS

Common side effects

When side effects do occur, they are typically mild and often associated with high doses. These include: 

• Digestive issues: Nausea, stomach cramps, and diarrhea.

• Skin reactions: Rashes or acne, especially on the chin and jawline, which may be caused by increased oil production. 

OVER DOSE

Overdosing on biotin is unlikely because it is a water-soluble vitamin that the body eliminates through urine when consumed in excess. Consequently, no tolerable upper intake level (UL) has been set for biotin, as there is no evidence of toxicity even at high doses. However, very large doses—especially from supplements—can cause side effects and may interfere with the accuracy of certain laboratory tests. It is advisable to consult a healthcare professional before starting biotin supplementation.

TOXICITY

Biotin toxicity is uncommon since it is a water-soluble vitamin and any excess is eliminated through urine. However, taking very high doses from supplements can disrupt laboratory test results, which may result in serious misdiagnoses. While clear symptoms of excessive biotin intake are not well established, the main concern is the potential side effects related to interference with diagnostic tests.