Less than a week after TIME magazine’s cover story on the mainstreaming of vegetarianism, new evidence is emerging about potential health dangers from observing a strict, meatless diet.

First, Swedish scientists at Umea University found that young vegans (those who shun all animal products, including eggs and dairy) may be missing out on essential vitamins and minerals. Writing in the American Journal of Clinical Nutrition, Christel L. Larson and Gunnar K. Johansson reported that vegans’ dietary habits “did not comply with the average requirements for some essential nutrients.” In particular, they found that vegans lacked appropriate levels of riboflavin, vitamin B-12, vitamin D, calcium, and selenium.

In an even more comprehensive British study involving nearly 8,000 subjects, a Cambridge University professor now says that children born to vegetarian mothers are up to five times more likely to be born with “deformities” and other birth defects. The scientist leading the research told a Europe Intelligence Wire reporter that “there is a clear association between child deformities and vegetarianism, and this is a cause for concern.”