#6 Vitamin A Overdose
As we said before vitamin deficiencies can result in hair loss. However, according to the American Academy of Dermatology, using too many vitamin A supplements or medication might cause hair loss.
Adults and children over the age of four should consume 5.000 IU of vitamin A each day, according to the Food and Drug Administration. Supplements with 2.500 to 10.000 IU are available. Anything more than that, and you risk having some hairs fall out.
The good news is that excessive vitamin A consumption is also a treatable cause of hair loss. Once the extra vitamin A is eliminated, hair should resume its normal growth.