Politicians in India are lobbying for a law to force dairies to add soluble vitamin A to milk, a change that could prove lucrative for ingredients suppliers.

Indian MPs from across parties have agreed to back the plan, which is aimed at reducing malnutrition, particularly among children.

MP Sachin Pilot has tabled a private member's bill in the Indian parliament to try and get a law on the matter enacted. The bill calls for an amendment to India's Prevention of Food Adulteration Act to force dairy companies to add a supplement that provides 2,000 units of vitamin A in every litre of milk. Raw milk contains 1,300 to 1,800 units of vitamin A in every litre, but most of the vitamin, soluble in fat, gets removed when fat is eliminated during processing, say supporters of the proposal.

The proposal deliberately aims to provide more vitamin A than milk contains naturally in a bid to help people in India, and children in particular, get their recommended daily intake. A recent survey by India's Health Ministry and Unicef found that 46 per cent of Indian children aged under three were malnourished. Meanwhile, India is estimated to be home to 40 per cent of the world's malnourished children. Vitamin A is an essential nutrient that benefits the immune system, eyesight and skin health.

Pilot's campaign has the support of the Global Alliance for Improved Nutrition, which is working to curb malnutrition in the developing world and is recognised by the United Nations. Unveiling the bill, Sachin told an Indian newspaper that milk industry representatives had expressed their support. But he added: "It would be naive to think that companies will add vitamin A on their own. The law is essential." Health minister Anbumani Ramadoss had shown a "positive response" to the proposal, he added.

If the bill became law it could open up a profitable new market for suppliers of vitamin A. Cows' milk consumption in India stood at 40 million tonnes in 2006, according to US Department of Agriculture figures — more than in any other country on Earth.