What the newspapers don't tell you...

OK, it may be good for me, even though I'm not pregnant. And if it is good for some of us, then I'll not stand in the way. But The Telegraph, like the other papers, does not tell the whole story:

"Folic acid may be added to bread and flour to reduce the number of babies born with birth defects if advice from experts at the Government's food watchdog is taken up.
A three-month consultation involving consumers, industry representatives and health groups is expected to be launched today.
This could lead to ministers approving the move."

Exactly what is folic acid?