I dont know about the white spots. But what did REAL GOOD to my nails was (Hum how do you say that in English: gelatine? No that `s definitely French jelly????) Well Jell-O is a famous brand. But the plain jelly, with no flavor. I used to make it with mint and cinamon. I never used stevia in there but that would also be and idea. It is REALLY a refreshing snack summertime.... and it helps plenty with nail problems.