General Description
Biotin is loosely categorized as a B vitamin. It is needed by the
body for the metabolism of carbohydrates, fats, and proteins. Biotin
deficiency is rare because it is found in many foods and is made
by microorganisms in the gastrointestinal tract. However, a deficiency
may result from eating large quantities of raw egg whites, or long-term
use of antibiotics. Avidin, found in raw egg, prevents biotin from
being absorbed into the blood stream. Antibiotics can kill the microorganisms
in the gastrointestinal tract, thus reducing the body's ability
to produce biotin. Symptoms of deficiency are nausea, loss of appetite,
numbness, muscle pains, depression, rashes, hair loss, high blood
cholesterol, and anemia.
Food sources
Good food sources of biotin include oatmeal, bananas, liver, sunflower
seeds, soybeans, eggs, butter, nuts, split peas, and mushrooms.
Health applications
- Brittle nails
- Seborrheic dermatitis
- Diabetes
Functions and uses
Biotin is a water-soluble nutrient that assists the body as a coenzyme,
enabling many vital chemical processes. It is involved in the breakdown
of fat, carbohydrate, and protein to produce energy. It is also
helpful in maintaining healthy sweat glands, hair, bone marrow,
and nerve tissue. Biotin helps the body produce digestive enzymes,
and antibodies. It aids in the utilization of other B-complex vitamins
such as folic acid, pantothenic acid, and vitamin B-12. It is also
a catalyst in the chemical reaction called carbon dioxide fixation.
This process assists in the movement and utilization of carbon dioxide
throughout the body, particularly during the processing of carbohydrates
and fats.
Brittle nails
Studies report that moderate doses of supplemental biotin may
help improve brittle fingernails.1,2 A study evaluated
45 patients who were given biotin supplements. 91 percent of the
patients evaluated showed definitive improvement regarding the
brittle nature of their fingernails. In four patients the results
were inconclusive.1
Seborrheic dermatitis
Seborrheic dermatitis, also known as cradle cap, is characterized
by a dry, scaly scalp. This disease occurs in infants who are
biotin deficient. Infants are potentially biotin deficient either
because of inborn disease that does not allow the vitamin to be
metabolized normally, or from the fact that infants are not born
with the microorganisms in their gastrointestinal tract that produce
biotin. There are conflicting studies about the efficacy of biotin
supplementation to treat the disease. Some report that administering
biotin intravenously gets rid of the disease in 8-30 days3,
while others report limited success, or none at all.4,5
Diabetes
Studies suggest that biotin supplementation may play a role in
improving glucose metabolism in noninsulin-dependent diabetes
mellitus.6,7 These studies are not conclusive and additional
clinical studies are needed.
Dosage and Toxicity
The RDI for biotin is 300 mcg for adults. It is included in most
B-complex and multivitamin supplements. Intake through diet and
regular gastrointestinal production makes biotin deficiency rare.
Because excess biotin is excreted through urination, it is considered
a non-toxic substance.
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