My hair is healthy and it takes a long long time for me to get split ends. My hair generally grows slow though and since vitamins speed it up I assume I'm lacking in some things.
I did notice when I drank a lot of protein shakes during heavy workout times of year that I had more baby hair growth coming in. I guess I best start experimenting with that.
I feel like I get protein and my stats show I get a normal amount but maybe it's more bio available in the powder form. At least for my particular system.
Low porosity, medium texture.

If it smells good put it in your hair, if it tastes good spit it out!