Corn tortillas will now contain this key ingredient in California. Here's why.

In an effort to prevent birth defects, California now requires food makers to add folic acid to corn masa flour used to make tortillas and other foods like tamales and pupusas.

Folic acid is a form of folate, which is a key B vitamin that is crucial for helping your body make new cells.

It's especially important during pregnancy, because it helps the neural tube, which becomes the brain and spine, develop, the Centers for Disease Control and Prevention explains.

"It is the only form of folate that's been shown to help prevent serious birth defects called neural tube defects (NTDs). NTDs are major birth defects of the baby's brain (such as anencephaly) and spine (such as spina bifida)," the CDC adds.

For nearly 30 years, the vitamin has been a required addition to enriched breads, cereals and pastas in the United States. Though this change in 1998 led to overall decreases in NTDs, some populations, including Hispanic infants, still suffer from disproportionately high rates.

The move to require folic acid in corn masa aims to particularly benefit Latina women, who are less likely to take it early on in pregnancy, according to public health data released by the state.

While California became the first state to make this requirement in January, other states are considering the move too.

A similar law takes effect in Alabama in June, according to the Associated Press, and legislation is also being considered in Florida, Georgia, Oklahoma and Oregon.

Texas, Delaware, New Jersey and Pennsylvania have also expressed interest in the issue, according to the advocacy group Food Fortification Initiative, the AP reports.

The CDC says about half of all pregnancies in the United States are unintended, which makes regular folic acid consumption important in reducing potential health risks.

"By the time you realize you're pregnant, it might be too late to prevent an NTD," the agency notes. "That is why getting 400 micrograms of folic acid before and during early pregnancy is important to help prevent NTDs."