If you are someone who has really weak nails, I would recommend adding more biotin rich foods into your diet or supplementing with biotin (or a vitamin B complex) if necessary.
Along with helping the body metabolize fats and carbohydrates, biotin has been linked to improved hair health, stronger nails and maintaining proper function of the nervous system.
You can find biotin in fruits, nuts and vegetables so chances are if you have a proper diet, you do not have a biotin deficiency.
A biotin deficiency can lead to a variety of skin problems including rashes, acne, psoriasis, dermatitis and overall itchiness so I would recommend supplementing with biotin if you have any of these issues.
Take home message: Eat more biotin rich foods such as fruits, nuts and vegetables and supplement with biotin if deficient, for healthier skin, hair and nails.