Normal LFT, Normal ultra sound, Terry's Nails?

I have what appears to be Terry's Nails or "half and half nails" on most of my fingers. I noticed them several years ago and since have had 3 full physicals. All LFT tests (including the rest of my blood work) came back normal though I was sent for an ultra-sound due to upper right abdominal pain. This showed a benign cyst about 1 inch in diameter, otherwise the liver was of normal size and appearance. The doctor said the cyst isn't large enough to cause symptoms and the pain is likely from my gall bladder, not my liver. He wasn't impressed by my nail discoloration and not concerned about liver disease (which he expressly indicated). Still, my nails become more profound over time. I'm 35 yrs old and have a history of heavy drinking which I fully devulged to my physician. Of course he told me to drink less alcohol but never seemed alarmed (I drink about a 6 pack a day, 5 to 6 days a week).

I'm very active and probably appear to be in prime shape (lean with good muscle tone). My blood work has always been normal with optimal cholestoral (low LDL/high HDL) and blood pressure. I get the feeling that because of this the doctor may be overlooking my concerns. From everything I've read Terry's Nails are almost always an indication of a serious systemic disease (namely liver or kidney). How concerned should I be? My doctor said if it was caused by liver/kideny issues my blood tests would not be normal. I hate to 2nd guess him and I do think he's a great doctor. I just can't put this concern to rest.

[Fuzzz]

One other possible cause of this problem is a nutritional deficiency.  One cause of liver disease is nutritional deficiency associated with alcoholism.  

Maybe your nails are trying to tell you that you are not eating properly because you are drinking most of your calories.  Maybe if you make changes now you can spare your liver permanent damage.  

http://www.nlm.nih.gov/medlineplus/ency/imagepages/2343.htm

http://www.nutramed.com/alcohol/alcoholneg.htm