Vitamins for hair and nails

Recently my hair has been thinning and my nails are peeling...is this a sign of a vitamin deficiency? If so, which vitamis affect this?

[Dr_Aparna]

Hi,
If your body is in good health, you can maximize your genetic growth cycle through taking the proper blend of amino acids and B-vitamins.  
It is also important to include B-6, biotin, Inositol and folic acid in the supplemental program.  It has been found that certain minerals including magnesium, sulfur, silica and zinc are also very important toward maintaining healthy hair.
Beta-carotene is also essential to hair growth.  This is because it is converted to vitamin A as the body needs it, helps maintain normal growth and bone development, protective sheathing around nerve fibers, as well as promoting healthy skin, hair and nails.
Since hair is protein, a diet that is too low in protein may cause some thinning in hair or a retardation in the growth cycle.  The converse is true,  If you eat a protein-rich diet it will often result in improved hair growth.
Some nutritional experts suggest the dietary utilization of calves liver, brewer's yeast, wheat germ and a daily dose of two tablespoons of granulated lecithin to maximize hair growth, strength and beauty.
Other good food sources for protein include fish, eggs, beans and yogurt.  Soy protein has also been found to be helpful in stimulating hair growth.
One study of the results of soy on the hair found that it not only strengthened the hair but caused it to grow. A great source of soy is tofu.
Excessive stress and some medications are conclusively known to retard hair growth.  Always consult your doctor BEFORE you undertake any new type of vitamin, mineral program or herbal program of any type to make sure it does not interfere with any medical treatment you may currently be on.
http://www.hairboutique.com/tips/tip214.htm
The one most important dietary measure you can take is to include plenty of green and yellow vegetables and fruits in your daliy eating.
Also you must rule out iron deficiency which is an important cause for thinning of hair.