Bollywood megastar Amitabh Bachchan has come on board to front a campaign to address the issues of malnutrition, stunting and infant mortality.

GSK Consumer Healthcare has launched Horlicks Mission Poshan, which will focus on first thousand days of a child's life which are critical for cognitive development, physical growth and immunity.

The campaign supports the government's Rashtriya Poshan Abhiyaan. Big B will be a part of many activities planned all-round the year including a 12-hour live telethon and awareness camps across schools and villages.

Amitabh took to social media to announce his association.

"Did you know that 50 per cent of world's undernourished children are in India, in our country. We need to start the fight against malnutrition now. I am taking the 1st step by joining the biggest movement to fight malnutrition," Big tweeted. He tagged Prime Minister Narendra Modi, NITI Aayog CEO Amitabh Kant and Women and Child Development Minister Maneka Gandhi.

Navneet Saluja, Managing Director, GSK Consumer Healthcare, said in a statement: "Our initiative has a singular goal - to help promote the need for nutritional needs across rural and urban India. We are fortunate to have Amitabh Bachchan partner us in this significant journey towards addressing the issue of malnutrition in our country."

Saluja said they are "committed to dialling up mass awareness around malnourishment and working with the civil society towards its eradication".