There is no logic in taking various kinds of suppliments to protect the hairs. Suppliments (multivitamins etc) are specifically given by doctors in cases where they find deficiency of vitamins or suspect low nutrition in the diet. For more light on the topic read from the internet and take reasonable steps. Learn about healthy and nutritious balanced diet and try to eat a variety of food substances (also eat more of seasonal fruits and vegetables - organic ones if possible ). Also read about hair growth
and the physiology involved to understand the basics. Avoid unnecessary medications or cosmetics as they can also harm you in the long run. Talk to a doctor if you have any specific health problems and get the right treatment course.