Biotin deficiencyis rare and mild, and can be addressed with supplementation. It is caused by the consumption of raw egg whites(two or more daily for several months) due the avidinthey contain, a protein which binds extremely strongly with biotin, making it unavailable. Such regimens have produced the only examples of biotin deficiency serious enough to produce symptoms.[22]

The first demonstration of biotin deficiency in animals was observed in animals fed raw egg white. Rats fed egg white protein were found to develop dermatitis, alopecia,[23]and neuromuscular dysfunction. This syndrome, called egg white injury, was discovered to be caused by a glycoprotein found in egg white, avidin.[citation needed]Avidin denatures upon heating (cooking), while the biotin remains intact.

Symptoms of biotin deficiency include:

Hair loss (alopecia)


Dermatitisin the form of a scaly, red rash around the eyes, nose, mouth, and genital area.

Neurological symptoms in adults, such as depression, lethargy, hallucination, and numbness and tingling of the extremities[8]

The characteristic facial rash, together with an unusual facial fat distribution, has been termed the "biotin-deficient face" by some experts. Individuals with hereditary disorders of biotin deficiency have evidence of impaired immune system function, including increased susceptibility to bacterial and fungal infections.[24]

Pregnant women tend to have a high risk of biotin deficiency. Nearly half of pregnant women have abnormal increases of 3-hydroxyisovaleric acid, which reflects reduced status of biotin.[24]Several studies have reported this possible biotin deficiency during the pregnancy may cause infants' congenital malformations, such as cleft palate. Mice fed with dried raw egg to induce biotin deficiency during the gestation resulted in up to 100% incidence of the infants' malnourishment. Infants and embryos are more sensitive to the biotin deficiency. Therefore, even a mild level of the mother's biotin deficiency that does not reach the appearance of physiological deficiency signs may cause a serious consequence in the infants.