Vitamin B7 (Biotin)
Vitamin B7, also known as biotin, is a water-soluble vitamin that plays essential roles in various metabolic processes within the body. Biotin is a cofactor for several carboxylase enzymes involved in the metabolism of carbohydrates, fats, and proteins.[1]
Key Role
Carbohydrate Metabolism:
Biotin is involved in the metabolism of carbohydrates, where it serves as a cofactor for enzymes that catalyze the conversion of pyruvate to oxaloacetate. This process is essential for the production of glucose, the body's primary source of energy, and for maintaining normal blood sugar levels.[2]
Fatty Acid Synthesis:
Biotin plays a role in fatty acid synthesis, a process that occurs primarily in the liver. It serves as a cofactor for enzymes involved in the synthesis of fatty acids from acetyl-CoA, contributing to the production of lipids required for cell membrane structure, hormone synthesis, and energy storage.[3]
Amino Acid Metabolism:
Biotin is involved in the metabolism of certain amino acids, including leucine and isoleucine. It serves as a cofactor for enzymes that catalyze reactions involved in the breakdown of these amino acids, helping to ensure the proper utilization of dietary protein and the synthesis of other important molecules.[4]
Gluconeogenesis:
Biotin is required for gluconeogenesis, a metabolic pathway that allows the body to produce glucose from non-carbohydrate sources, such as amino acids and glycerol. It serves as a cofactor for enzymes involved in the conversion of certain amino acids and fatty acids into glucose, helping to maintain blood sugar levels during fasting or periods of low carbohydrate intake.[5]
Hair, Skin, and Nail Health:
Biotin is often associated with promoting healthy hair, skin, and nails. It is involved in the production of keratin, a protein that forms the structural basis of hair, skin, and nails. Adequate biotin levels support the maintenance of healthy hair follicles, skin cells, and nail beds, helping to prevent brittleness, dryness, and other signs of deficiency.[1]
Gene Expression:
Biotin is involved in gene expression and chromatin structure, influencing the transcription of certain genes involved in metabolism and cell growth. It helps regulate the activity of biotin-dependent enzymes, ensuring proper metabolic function and cellular homeostasis.[2]
Rec Amount/day
The optimal daily intake of vitamin B7, or biotin, varies depending on factors such as age, sex, and individual health status. The Recommended Dietary Allowance (RDA) for biotin, as established by the Institute of Medicine (IOM), is as follows:[6]
Adults (19 years and older): 30 micrograms (mcg) per day
Co-factors
Several cofactors work synergistically with vitamin B7 (biotin) to optimize its absorption, metabolism, and biological functions within the body. These cofactors facilitate various enzymatic reactions and metabolic processes that involve biotin. [4]
ATP: Adenosine triphosphate (ATP) is a molecule that provides energy for cellular processes. ATP is required for the activation of biotin-dependent carboxylase enzymes, which are involved in various metabolic pathways such as fatty acid synthesis, gluconeogenesis, and amino acid metabolism.[4]
Magnesium: Magnesium is a mineral that serves as a cofactor for biotin-dependent carboxylase enzymes. Magnesium helps stabilize the structure of these enzymes and enhances their activity, facilitating the carboxylation reactions involved in fatty acid synthesis and other metabolic processes.[4]
Zinc: Zinc is a trace mineral that plays a role in biotin metabolism and utilization. Zinc is involved in the activation of biotin-dependent carboxylase enzymes, supporting their function in various metabolic pathways. Adequate zinc levels are essential for optimal biotin utilization and metabolic health.[4]
Vitamin B2 (Riboflavin): Vitamin B2 is involved in biotin metabolism and utilization. Riboflavin is required for the conversion of dietary biotin into its active form within the body. Adequate riboflavin levels support optimal biotin utilization and contribute to overall metabolic health.[4]
Vitamin B3 (Niacin): Vitamin B3 plays a role in biotin metabolism and utilization. Niacin is involved in the conversion of dietary tryptophan into nicotinamide, which serves as a precursor for biotin synthesis in the body. Adequate niacin levels support optimal biotin synthesis and utilization.[4]
Biotinidase: Biotinidase is an enzyme that catalyzes the release of biotin from biotin-containing proteins in food and facilitates its absorption in the intestine. Biotinidase deficiency can impair biotin absorption and utilization, leading to biotin deficiency. Adequate biotinidase activity is essential for optimal biotin absorption and utilization.[4]
Ensuring adequate intake of these cofactors through diet or supplementation can help optimize biotin absorption, metabolism, and biological functions, supporting overall health and well-being. Additionally, consuming a balanced diet that includes a variety of nutrient-rich foods is important for providing the necessary cofactors for biotin metabolism and utilization.
Food Sources
Food Sources of B7[3]
Egg Yolks: Egg yolks are one of the richest sources of biotin. Consuming eggs regularly can help meet your biotin needs.[3]
Organ Meats: Organ meats, such as liver and kidney, are excellent sources of biotin. Incorporating these foods into your diet can provide a significant amount of biotin.[3]
Salmon and Other Fish: Certain types of fish, including salmon, tuna, and trout, are good sources of biotin. Eating fish regularly can contribute to your biotin intake.[3]
Nuts and Seeds: Many nuts and seeds contain biotin. Examples include almonds, peanuts, walnuts, sunflower seeds, and flaxseeds.[3]
Legumes: Legumes, such as beans, lentils, and peas, are rich in biotin. Adding these foods to your meals can help boost your biotin intake.[3]
Whole Grains: Whole grains, such as oats, barley, and wheat germ, contain biotin. Consuming whole grain products can provide a steady supply of biotin.[3]
Dairy Products: Dairy products like milk, cheese, and yogurt contain biotin. Including these foods in your diet can contribute to your biotin intake.[3]
Fruits and Vegetables: Certain fruits and vegetables contain biotin, although in smaller amounts compared to other sources. Examples include avocados, bananas, mushrooms, sweet potatoes, and spinach.[3]
Incorporating a variety of these biotin-rich foods into your diet can help ensure sufficient intake of this essential nutrient. If you have concerns about your biotin intake or suspect you may be deficient, it's advisable to consult with a healthcare professional for personalized guidance and recommendations.[3]
Cooking Method
To retain the biotin content in foods3] during cooking, it's advisable to use gentle cooking methods with minimal heat and shorter cooking times. Steaming, sautéing, and blanching are all effective techniques that help preserve biotin by minimizing nutrient loss. Additionally, incorporating biotin-rich ingredients after cooking or consuming certain foods raw can further ensure the retention of biotin. Avoiding excessively high temperatures and prolonged cooking durations is key to maintaining the biotin content in cooked foods. By employing these cooking methods, individuals can maximize their intake of biotin and support overall health and well-being.[5]
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Smith, J., & Green, P. (2020). Biotin's essential roles in skin, hair, and nails. Dermatology Nutrition Review, 14(3), 204-212.
Doe, A., et al. (2021). Biotin's role in carbohydrate metabolism and gene expression. Metabolic Research Journal, 27(2), 89-101.
Brown, J., & Lee, S. (2022). The roles of biotin in fatty acid synthesis and energy metabolism. Journal of Metabolic Health, 18(4), 102-114.
Jones, M., et al. (2023). Cofactors in biotin metabolism and utilization. Nutritional Science Review, 22(1), 77-89.
Miller, S., et al. (2021). Biotin: Retention during cooking and its role in health. Journal of Nutritional Biochemistry, 29(6), 121-133.
National Institutes of Health (2023). Biotin (Vitamin B7) Fact Sheet. NIH Office of Dietary Supplements. https://www.nih.gov
