<<Disclaimer: Verify this information before applying it to your situation.>>
The pediatric gastrointestinaligist that diagnosed my daughter with
Celiac told us her hair would become thicker as she was on a GF diet for
a period of time. (I don't know if it is related or just natural for a
toddler, but she has been on a GF diet for approx 6 months and her hair
is getting thicker.)