boitin

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Biotin

Elson M. Haas M.D.

(Excerpted from Staying

Healthy with Nutrition:

The Complete Guide to Diet and Nutritional

Medicine )

Biotin, a fairly

recently named B vitamin, was discovered by the deficiency symptoms created

through consuming large amounts (about 30 percent of the diet) of raw eggs.

Avidin, a protein and carbohydrate molecule in the egg white, binds with biotin

in the stomach and decreases its absorption. Cooking destroys the avidin, so the

only concern about this interaction is with raw egg consumption. Otherwise,

biotin is one of the most stable of the B vitamins.

Sources: Many foods contain biotin, but most have only trace

amounts. It is hard to obtain enough biotin from the diet. Luckily, our friendly

intestinal bacteria (lactobacillin) produce biotin. This vitamin is found in egg

yolks, liver, brewer’s yeast, unpolished rice, nuts, and milk.

Functions: The biotin coenzymes participate in the

metabolism of fat. Biotin is needed for fat production and in the synthesis of

fatty acids. It also helps incorporate amino acids into protein and facilitates

the synthesis of the pyrimidines, part of nucleic acids, and therefore helps the

formation of DNA and RNA.

Uses: A common use of biotin is to help normalize fat

metabolism and utilization in weight-reduction programs, and to help reduce

blood sugar in diabetic patients, with a dosage of between 200–400 mcg. per day.

Biotin has also been in wide use to prevent or slow the progression of graying

hair or baldness. This may work, however, only when these symptoms are related

to biotin deficiency; although, because of the nutrient and protein support of

biotin, it may indeed have some hair-stimulating effect.

Biotin is often used for problems such as dermatitis or eczema, especially in

infants, most often with appropriate intake of other B vitamins, such as

riboflavin, niacin, and pyridoxine and vitamin A. It has also been used to treat

muscle pains, though skin and hair are the main focus of supplementation. More

recently, biotin has been used for diabetics and those with an overgrowth of

intestinal yeast.

Deficiency and toxicity: There is no known toxicity with

biotin, even in high amounts. Excesses are easily eliminated in the urine.

Deficiency symptoms are also uncommon. Unless we are on a raw-egg diet or have

taken a lot of antibiotics, especially sulfa, which diminish our

biotin-producing intestinal bacteria, we are usually secure against biotin

deficiency.

The raw-egg study generated symptoms such as fatigue, nausea, loss of

appetite, muscle pains, and depression. Other symptoms that have since been seen

with biotin deficiency include dry and flaky skin, loss of energy, insomnia,

increases in cholesterol, sensitivity to touch, inflamed eyes, hair loss, muscle

weakness, and impaired fat metabolism. Several enzymes depend on biotin to

function properly. Without them, we cannot utilize our foods as well.

Biotin deficiency is sometimes seen in babies when a biotin-deficient formula

is used or there is some problem with intestinal biotin synthesis. If this

occurs, hair loss, muscle weakness, irritated eyes, and a scaly rash may result.

In some studies in juveniles, biotin deficiency was seen to result in hair loss

and occasional balding. With more advanced biotin deficiency in people of all

ages, elevation in cholesterol, anemia, or changes in the electrocardiogram may

occur.

Requirements: The recommended level of biotin needed in the

diet ranges from 150–300 mcg., depending on how well it is produced by the

intestinal bacterial flora. Probably 300–400 mcg. is a safer range. We need

extra biotin if we consume raw eggs or have used antibiotics, especially the

sulfa drugs. Biotin requirements are also higher during pregnancy and lactation.

Infants require at least 50 mcg. per day. The need rises to an RDA of 120 mcg.

at ages 7–10; after age 11, it is over 200 mcg. A common amount of biotin in

vitamin B supplements is 400 mcg.

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