Nearly 80 per cent of the urban middle class in Pune have low vitamin B 12 levels while the record is better among the slum and village dwellers. "People who consumed meat more than twice a week had better vitamin B 12 levels," says Dr C S Yajnik, coordinator of the "Coronary risk of insulin sensitivity in Indian subjects," (CRISIS) a study done by KEM hospital.

Since vitamin B 12 occurs naturally only in animal products (eggs, meat, milk), a vegan diet can produce a deficiency unless one uses supplements or eats enriched food, Yajnik said. He was participating in the National Centre for Cell Science's diabetes research group meeting on Tuesday and said that KEM hospital has now tied up with the Department of Biotechnology (DBT), Government of India to find "milk fermenting bacteria" that can also make vitamin B-12.

"The ultimate source of vitamin B-12 in nature is microbes," Yajnik said. Changing lifestyles, food habits, lack of exercise and stress at work have been incriminated as the risk factors for diabetes mellitus. The deficiency of Vitamin B-12 among vegetarians has led to a rise in the incidence of stroke and heart attacks. Deficiency of vitamin B 12 increases the concentration of a chemical called homocysteine in the blood which causes blocks in arteries and veins. "These blocks in turn are responsible for heart attacks and strokes," said Yajnik.

The richest dietary sources of vitamin B 12 are liver, especially lamb's liver and kidneys.

Eggs, cheese and some species of fish also supply small amounts. The study had examined some 600 urban middle class men and women in Pune and its slums.

"While the study had investigated the relationship between body fat percent and its distribution to risk factors for type 2 diabetes and coronary heart disease in middle aged rural and urban men, they also found that nearly 80 per cent of the urban men had low vitamin B-12 levels.

In the slums, at least 40 per cent of the men had low vitamin B-12 levels," said Yajnik.