A simple question.. or maybe not, about water/iron.

[MissHair]

Hi everyone. Its been a while. Ive got a complicated question to ask, I always confuse things so Im gonna try to make this as simple as possible..

So Ive heard iron and drinking plenty of water is good for your hair.. But on what area of the hair does it have an affect?

The entire hair you have grown out? Like from root to tip or just the root and the new growth? Because Im wondering if like half my hair is in bad condition even when I drink water/take iron and only the new growth is more shiny and healthy.

[Dientje]

I can only think of the effect it has on your blood. Iron helps your blood carry oxygen, which is important for all body functions. And more water helps your system to secrete toxins more easily. So maybe it'll benefit your hair by increasing the amount of nutrients brought to the hair follicle, so the hair follicle is stronger and the new hair is better.
I don't think that changing your diet will benefit the length of your hair in any way. It essentially is dead material, just like your nails.
I don't know if this is correct, I'm just sharing my thoughts.

[Gumball]

It would only help new growth simply because you grow from the roots and not the tips. It's like if you were taking something for your nails then it would help new nail growth and not the tips of your nails. :)

[MissHair]

Makes perfect sence, thanks!! :)

[Kirin]

The hair length is dead, and has no circulatory system, so things you take in are only good for the follicle. Where the hair is produced is where the nutrients go making hair grow faster, or better, thicker as the follicle gets more blood and nutrients. However once hair is "made" it gains no more from anything you take in internally.