If you have obvious, jagged vertical ridges on your nails, you have poor absorption in either the stomach or small intestine, or both. Slight vertical ridges easily buffed off are normal.
Nails Diagnostics
If the nails are weak and bend/break easily, then you are low on essential minerals and possibly gelatin. Emergen-C and Calcium and Oatstraw Tea will help with this. Use gelatin as a thickener in gravies or just swallow empty gelatin capsules.
If you have a “hump” on your nail, you have severe deficiencies. Go on a tonifying/rebuilding protocol right away – start including super-foods in your diet regularly and digestive enzymes so you can absorb nutrients.
White spots do not mean what people think they mean. They are signs of acute stress that interrupted your digestion and elimination. They do not mean consistent deficiencies of any kind.