How may one repair hair follicle damage naturally?

i am training to be a hairdresser and to be honest once hair is damaged then you cannot undoe the damage but you can prevent furthur damage to the hair, i would invest in a good shampoo, conditioner and conditioning spray, also regular exercise and fresh air, a good diet and plenty of fresh fruit and water also try taking vitamin tablets and see how you go i would give it 6 months at least for the hair to repair itself and for new hair folicles to growx