Biotin – Vitamin B7
Biotin is a member of the B complex family. It is also known as vitamin B7, vitamin H, coenzyme R, and W factor. Its scientific name is cis-hexahydro-2-oxo-1H-thieno[3,4-d]-imidazole-4-valeric acid.
Biotin is a water-soluble vitamin. This means it cannot be stored in the body, but is excreted in urine. Biotin can be destroyed by heat, cooking, exposure to light, prolonged contact with water, baking soda, or any other alkaline substance.
Biotin is essential to all organisms, but it can only be synthesized by bacteria, yeasts, molds, algae, and some plant species. Humans obtains biotin from foods such as eggs, cooked liver, pork, salmon, yeast, whole wheat bread, cheddar cheese, avocados, raspberries, and raw cauliflower. Some biotin is also synthesized by bacteria in the human intestine.
Biotin is used by every cell in the body. It binds with several essential enzymes, and for this reason is considered an enzyme cofactor.
Apart from being a vital cofactor, biotin is essential in carbohydrate metabolism and the synthesis of fatty acids. It is also involved in the transformation of amino acids into protein.
Biotin is involved with cell growth and division through its role in the manufacture of DNA and RNA, the genetic components of cells. It contributes to the health of skin, hair, nerves, bone marrow, sex glands, and sebaceous glands. Adequate biotin is required for healthy nails and hair, and biotin deficiency is one factor in balding and the premature graying of hair. Biotin deficiency can also cause weak, splitting nails. Seborrheic dermatitis, or Leiner’s disease, which is a non-itchy, red scaling rash affecting infants during the first three months of life, is also treated with biotin and other B complex vitamins.
Biotin has been used in conjunction with other nutrients as part of weight loss programs, as it aids in the digestion and breakdown of fats.
High doses of biotin are sometimes used by the allopathic medical profession to treat non-insulin dependent diabetes. It does not appear to have much effect alone, but a combination of chromium picolinate and biotin has been shown to improve glucose management in some patients who have type 2 diabetes.
Biotin is also used to treat pain in patients with peripheral neuropathy, a complication of diabetes, and patients with Duchenne muscular dystrophy, who suffer from metabolic deficiencies.
The adequate intake (AI) of biotin in the United States, as calculated by the Food and Nutrition Board of the Institute of Medicine, is :
- 30 mcg for adults and pregnant women
- 35 mcg for breastfeeding women.
- for children begins with 5 mcg for infants,
- rising with age to 25 mcg for older teens.
Supplementation ranges from 100–600 mcg per day, and can be obtained in the form of brewer’s yeast (which contains biotin as part of the B complex), or as an individual biotin supplement.
The body needs biotin on a daily basis since it is water soluble and not stored to any great extent. Biotin requirements increase during lactation. Researchers have investigated the need for supplemental biotin during pregnancy. Nearly 50% of pregnant women appear to be deficient in biotin, which could result in birth defects according to studies that have been conducted on animals. Scientists suggest that biotin be included in prenatal multivitamin formulas.
Those taking long-term antibiotics may need to supplement their diets with biotin to compensate for the biotin normally produced by bacteria in the gut that are killed by antibiotics.
Certain individuals are at risk for biotin deficiency, including: infants who are fed biotin-deficient formula or who have inherited deficiency disorders; patients who are fed intravenously for an extended period; and anyone who habitually eats raw egg whites, because they contain a protein called avidin, which prevents the absorption of biotin (avidin is rendered inactive when eggs are cooked).
Because biotin is synthesized in the gut, deficiency symptoms are rare. Symptoms of deficiency may include weakness, lethargy, grayish skin color, eczema (which may appear as a scaly red rash around the nose, mouth, and other orifices), hair loss, cradle cap in infants, muscle aches, impaired ability to digest fats, nausea, depression, loss of appetite, insomnia, high cholesterol levels, eye inflammation, sensitivity to touch, anemia, and tingling in the hands and feet.
Symptoms of extreme biotin deficiency include elevation of cholesterol levels, heart problems, and paralysis. When extreme deficiency is a problem, the liver may not be able to detoxify the body efficiently, and depression may develop into hallucinations. Infants may exhibit developmental delay and lack of muscle tone.
Biotin deficiency could result in a loss of immune function, since animal experiments have shown that biotin deficiency leads to a decrease in white blood-cell function. Because biotin is essential to the body’s metabolic functions, any deficiency could result in impaired metabolism as well.
There have been no reports of overdosing of biotin, even at very high doses, primarily because any excess is excreted in the urine.
There are no side effects associated with biotin supplementation.
Biotin works in conjunction with all the B vitamins, which are synergistic, meaning they work best when all are available in adequate amounts.
Raw egg white contains the protein avidin, which prevents absorption of biotin.
Sulfa drugs, estrogen, and alcohol all increase the amount of biotin needed in the body.
In addition, anticonvulsant drugs may lead to biotin deficiency.
Long-term use of antibiotics may prevent the synthesis of biotin in the gut by killing off bacteria that help the body produce biotin. Supplements of lactobacillus may help the body make sufficient amounts of biotin after long-term antibiotic use.
There is some evidence that cigarette smoking increases the need for biotin.