QUOTE (Spot @ Feb 11 2008, 07:40 PM)

i remember hearing that changes in the white half-moon shape part of the nail can indicate warning signs of a medical condition or an insufficiency? does anyone have a source for that?
I think they are calcium deposits...
But I don't even have them except on my thumbs and I am not deficient in calcium.
I do have this weird vertical line on my left thumb though that goes from the root to the top of the nail and is red, and often turns black and at the top of the nail it splits there.