"If my face and my voice is needed to the cause of awareness for Head Injury and Hepatitis... I have committed to it," Amitabh tweeted Sunday.
He also took to Facebook to share more about his commitment.
"Dedicated today (Saturday) to the medical profession... my commitment to be involved in the campaigns to be conducted for Head Injury and Hepatitis. Honoured by the AAPI organisation - American Association of Physicians of Indian origin," he posted Sunday.
The 72-year-old believes he is the "perfect example to be associated with these visions".
"I am perhaps the perfect example to be associated with these visions that the doctors and physicians of Indian origin, now living in USA, wish to entertain during the coming years."
"I have been through so many of these ailments and have personally battled them so, I am able to understand the need for its propagation and relief," he posted on his blog srbachchan.tumblr.com.
The "Don" star has been associated with Unicef as a Global Ambassador for polio eradication since 2005.
