I have brittle nails that never grow more than a mm without splitting and currently very short hair which I absolutely hate! I have read that Biotin and Vit B complex are beneficial for hair and nails. I doubt i'm clinically deficient in anything as I eat a decent diet, but I do remember my Mum giving the cat Vit B (brewers yeast) tablets when her fur was looking tatty and it really helped .
Not that I want shiny whiskers and a gleaming full tail, but still!
Just wondered if it was worth giving supplements a go or whether I'd be weeing money down the drain!