White marks on fingernails
White marks on fingernails is a classic sign of zinc deficiency. So are ridges that run across the nail. If you see white marks or stripes on three or more of your nails, then it’s indicative that you’re severly lacking in zinc. Zinc is rapidly depleted by stress and in men, by sex; semen is rich in zinc!!
So, do supplement with 15mg of zinc a day, and also eat zinc-rich foods like oysters; the best source of zinc. Other sources includes fresh ginger, lamb, pecan nuts,fresh green peas, dried split peas, turnips, haddock, shrimp, eggs, Brazil nuts, and wholegrains such as rye and oats, peanuts and almonds.