My hair has been gradually thinning over the past 3/6 months, mostly on the top of my head. I’ve had my bloods checked and apart from a vitamin d deficiency, which I am now taking supplements for, they are all normal and the GP is not forthcoming with any advice. Has anyone had similar or can offer any advice on where to go from here? I am 28 and generally in good health. My hair is colours but by no means over processed and my hairdresser says my hair overall is in very good condition.