June 18, 2003 -- Researchers have long known that a strict vegetarian diet -- one that excludes all animal products -- can lead to vitamin B-12 deficiency, and possibly heart disease. Now, new research suggests that even those who follow a more lenient vegetarian diet are also at risk.

In the July issue of the American Journal of Clinical Nutrition, German researchers tracked 174 apparently healthy people living in Germany and the Netherlands.

They found that 92% of the vegans they studied -- those who ate the strictest vegetarian diet, which shuns all animal products, including milk and eggs -- had vitamin B12 deficiency. But two in three people who followed a vegetarian diet that included milk and eggs as their only animal foods also were deficient. Only 5% of those who consumed meats had vitamin B12 deficiency.