spina bifida?!

As I was studying embryo, my mom was sitting on the couch preparing for a bible study. 
I reach the slide mentioning spina bifida and just out of curiosity, I ask my mom, "Hey, do you know what spina bifida is?"

Mom: Yeah...it's when the neural tube doesn't close properly, which causes some problems for babies. Folic acid is important for the mothers to take while they're pregnant to prevent it.  


By that time, I didn't know if the folic acid part was true...but I read on to the next slide and it said..
" 70% of spina bifida cases are preventable by taking adequate amounts of folate vitamin during pregnancy. (vitamin B9 = folic acid) "


....please write my exam for me?!?! T_T