<unk>  can have a very serious, even fatal, outcome if it is allowed to progress without treatment.  Signs and symptoms of<unk>  can develop in persons of any age, race, or gender.<unk>  rarely occurs in healthy individuals, since the daily requirements of biotin are low, many foods contain adequate amounts, intestinal bacteria synthesize small amounts, and the body effectively scavenges and recycles biotin from bodily waste. However, deficiency can be caused by excessive consumption of raw egg-whites over a long period (months to years).  Egg-whites contain high levels of avidin, a protein that binds biotin strongly. Once a biotin-avidin complex forms, the bond is essentially irreversible.  The biotin-avidin complex is not broken down nor liberated during digestion, and the biotin-avidin complex is lost in the feces.  Once cooked, the egg-white avidin becomes denatured and entirely non-toxic.
Initial symptoms of<unk>  include:
If left untreated, neurological symptoms can develop, including:
The treatment for<unk>  is simply to start taking some biotin supplements.
Biotin deficiency
Chromium deficiency
Copper deficiency
Manganese deficiency 
Zinc deficiency
Lead poisoning
Biotinidase deficiency
Folate deficiency