Biotin - Vitamin B8

Vitamin B8, Vitamin H, D-biotin. Member of the B-complex vitamins, it is relatively stable in heat, light, and oxygen. Biotin forms part of several enzyme systems and is necessary for normal growth and body function. It helps in the synthesis of fatty acids, in energy metabolism, and in the synthesis of amino acids and glucose. It promotes normal health of sweat glands, bone marrow, male gonads, blood cells, nerve tissue, skin, hair.Biotin is absorbed in the upper part of the small intestine; is bound to plasma proteins and distributed to all tissues.

Main storage sites are in the liver and kidneys. Excess biotin is excreted in the urine.

FOOD SOURCES

Brewer's yeast, cereals, brown rice, nuts, bulgur wheat, butter, liver and kidneys, oily fish, cheese, egg yolks, green peas. Some biotin is synthesised in the body by intestinal bacteria. Raw egg whites contain a glycoprotein called avidin which binds to biotin and renders it non-bioavailable.

SUPPLEMENTATION

Synthetic biotin from fumaric acid.

SIGNS OF DEFICIENCY

Alopecia, anemia, anorexia, depression, dry scaly dermatitis, fatigue, glossitis, hypercholesterolemia, loss of taste, myalgia, nausea, pallor, panic, skin disorders, sleepiness, smooth and pale tongue, vomiting.

SIGNS OF TOXICITY

Toxicity has not been observed.

MINIMUM DAILY REQUIREMENT

Subject of some disagreement. Estimates range from 30mcg to 300mcg.