I have vertically-ridged nails. I read somewhere that it has to do with the stomach not being able to produce enough hydrochloric acid. This is typical of blood type A's.
I suspect that this is the reason that drinking coffee, having a little more salt in the diet is good for us. They stimulate the production of hydrochloric acid. However, nothing I have tried so far has helped.

Oh, I almost forgot. I have been taking probiotics, cod liver oil and silica liquid, as well as following the BTD, for several years. I'm feeling very well but I still have the ridges.

Can someone tell me if krill oil is good for Type A's?