I just gave Persia a nice brushing. She's not a long-haired cat but she
still has a nice ruff around her neck. Well, I noticed it's turning
brown. Same thing with her chest.
Tyrosine deficiency?

Another possibility is biotin deficiency. That affected our Ishmael;
he had FUS and was put on a special prescribed food for it which
contained a lot of egg. One of the few ways humans can get biotin
deficiency is by eating a lot of raw egg - the classic case in the
textbooks was an alcoholic who lived on red wine and raw eggs. Its
effect on humans is premature greying. Ishmael's fur went from black
to various shades of brown and dirty brownish-grey in a few months.
Giving him biotin supplements (one human-sized daily capsule every
week, stirred into his food) turned it black again in a few weeks
with no other change to his diet.

Can aging humans take a bunch of it as a supplement to bring back
their original hair color?

If your diet is eggs and booze and you've gone grey at 30, biotin will
certainly help.

Biotin is not easy to get hold of. We had contacts with a specialist
supplements firm, and bought the one bottle they had on their shelves -
it was just out of date.

(I just googled and was surprised - it has recently become a fad
supplement to combat greying and increase hair growth in humans,
so it's probably easier to get than it was. I suspect most of the
claims made for it are hype).

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Jack Campin, 11 Third Street, Newtongrange, Midlothian EH22 4PU, Scotland
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