Biotin, otherwise known as vitamin B7, is one of eight essential vitamins the body requires to function. Biotin acts as a carrier of carbon dioxide, helps with the synthesis of fat, aids in weight loss and the metabolization of amino acids. It is also linked to keeping hair, skin and nails healthy. Through normal dosages, Biotin does not have any known side effects. An excess use of the vitamin, however, can have side effects that range from positive to negative.
Eosinophilic Pleuropericardial Effusion
Although rare, there is one documented case where a woman who took very high doses of biotin, mixed with vitamin B5, and developed a condition called eosinophilic pleuropericardial effusion. This condition is life-threatening, and means that blood or air are present in the pleural space, which can cause infection. In this specific case, the condition stopped immediately once the mixture of biotin and B5 was ceased.
Birth Defects and Miscarriages
In animal studies, when pregnant rats are under high doses of biotin the possibility of miscarriage is increased greatly, as well as birth defects, because the biotin makes the rats' placenta decrease in size, although the specific reason is unknown. It is not proven whether this happens in human pregnancies, but during pregnancy of all mammals a biotin deficiency is evident.
Rapid Growth of Hair and Nails
High levels of biotin in one's system results in rapidly growing hair and nails, as well as making the hair very shiny and healthy. It may even prevent hair loss and retain hair colors. This may be good for awhile, but the phrase too much of a good thing may be true. The body may compensate for too much biotin with excess sweating and urinating.