Guajava - Guajava demonstrates antifungal, antibacterial, anti-inflammatory, laxative, and analgesic properties. It is used to treat herpes ulcers, ringworm, dermatitis, and urinary tract infections. Guajava is related to cassia and senna, and contains anthraquinones found in those other species as well.
Vitamins B, particularly biotin (vitamin B7) and B12 are important to keep healthy nails. If your nutrition lacks in vitamins B, nails will be dry and brittle. Vitamin C deficiency is associated to brittle nails and may cause infections of nail tissues.
A failure to consume an adequate amount of nutrients can cause flaky and weak nails. Certain nutrients in particular can affect nail health. An iron deficiency, which is more common in women with heavy menstrual periods or people who use ibuprofen excessively, is an essential nutrient needed to produce healthy nails.