A good diet can help improve your nails, and taking the right vitamins will result in harder nails. Want to fill in the ridge's in your nails and get stronger nails? 1. Eat high-quality protein and fiber foods including eggs, grains, legumes, nuts and seeds. 2. Make sure your diet has a good combination of fresh fruits and vegetables. 3. Sulfur- and silicon-rich foods like onions, broccoli, fish and sea vegetables all help to harder your nails. 4. Eat foods high in B vitamins. Want to supplement your diet? Try looking for a base coat or polish infused with Calcium and Vitamins (especially B5). These can be found at any local drugstore or beauty supply store. Use daily to create a natural look and make nails harder.