Have you tried taking biotin supplements to improve hair thinning or hair loss (alopecia), but found all it did was strengthen your nails? The reason being is that biotin supplementation works best when a person with alopecia has a true biotin deficiency. But, a true biotin deficiency is rare, especially in the developed world. In fact, biotin deficiencies are not a common cause for those experiencing hair loss. A study published last year in the International Journal of Tric