Hello, I can understand your concern for your grey hair and hair fall problems. I would like to tell you that greying of hair is mostly hereditary and no one can stop it. You can hide your grey hair by using ammonia free hair colour, but you can not convert your grey hair to black hair. Multivitamin tablets will never help to treat your hairfall or grey hairs, so stop using it for that purpose. But you can prevent hair falls and for that i would recommend you few simple things.... 1. Use warm natural oils like coconut or olive oil to massage into your scalp, leave it for an hour or so or possible overnight and then shampoo your hairs. 2. You can rub your scalp with natural juice like onion or ginger juice, leave it overnight and then wash it thoroughly in the morning. 3. Anti oxidants are useful for better hair, so you can have a diet rich in vitamin C and E. You can also apply warm green tea on your scalp, which is a very good antioxidant and strengthen your hair roots. 4. Also do meditation regularly to remain stress free, because stress is one of the major cause of hairfall. Start doing all these remedies and you will see benefit within a month or so... Hope this answers your question and let me know if you have any further relevant questions.