According to WebMD, a healthy diet that includes B-12 helps hair stay strong, healthy and prevents possible hair loss, but it does not promote hair growth. WebMD suggests consuming a well-balanced diet that includes foods rich in fatty acids, vitamins B-6 and B-12 and folic acids.
In addition to a multivitamin, WebMD suggests eating nutritious foods that contain B-12 and other nutrients. Meat, chicken, fish and dairy products are good sources of B-12. Bananas, potatoes and spinach provide B-6. Folic acid sources include whole grains, beans and lentils. Omega-3 fatty acids are prevelant in fish, walnuts, almonds and acidic citrus fruits.