Although nutrition does play a role in hair loss and in the overall health of your hair, only extreme nutritional deficiencies or excesses will cause hair loss. For instance, people with anorexia and bulimia may temporarily lose hair. So will others suffering from malnutrition.
"It's pretty rare in the United States," says Bertolino. "If someone was on a real strange, restrictive diet, it could happen to them."
Megadoses of some vitamins--particularly A and E--and an iron deficiency may lead to hair loss. People who claim they can determine which vitamins are lacking in your diet by analyzing your hair, however, are not speaking from a scientifically sound basis. The test used with this type of hair analysis--atomic absorption spectrophotometry--is a legitimate analytical chemistry method; however, used on hair, the results of this test do not correlate with nutritional status, says Shupack. "Because of the sociological importance of hair, a lot of people try to cash in on it," he says. "Hair analysis is all witchcraft as far as I'm concerned."
There are, however, a few legitimate hair tests for substances such as arsenic and lead.
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