folate vs. folic acid: why it's important to know the difference

You may know of folate as one of the most important prenatal vitamins that a woman should concern herself with (certainly one of the most well-known).  This is arguably a very critical vitamin, as it helps to prevent neural tube defects in the growing fetus. 

The neural tube consists of the brain and spinal cord, and defects can lead to spina bifida (a malformation of the spine which can cause nerve damage and paralysis of the legs), anencephaly (underdevelopment of the brain), and encephalocele (incomplete formation of the skull).  

These are certainly tragedies that we would all like to avoid – and luckily, ensuring you are getting adequate levels of folate or folic acid prior to and in the very early stages of pregnancy will prevent these conditions from developing in most cases.

There are many other important functions and developments that folate is involved in as well, including:

  • the production of new DNA and RNA, and cell growth and development
  • ensuring a healthy birth weight
  • the prevention of spontaneous abortion
  • prevention of mental retardation
  • preventing deformations of the heart, mouth and face
  • brain and nervous system development
  • aids in red blood cell production (for this reason, a deficiency can lead to anemia)

So we can see that this is indeed a very important nutrient.

However, it is evident that the terms ‘folic acid’ and ‘folate’ are being used interchangeably by many health professionals, books, and websites advising pregnant women on what to eat and supplement with during pregnancy.

So what is the difference?

Folate is the naturally occurring version of vitamin B9, whereas folic acid is the synthetic form used in supplements.  While both versions do help to prevent neural tube defects, only folate crosses the placenta.

The metabolism of folic acid is a bit more complex, as well, compared to folate.  Whereas folate is metabolized in the digestive system, folic acid is metabolized in the liver and requires a specific enzyme, which is in short supply.  This conversion is very inefficient and results in much unconverted folic acid freely circulating throughout the body.  

Not only is this folic acid un-useable to our cells, it also interferes with the activity of our natural killer cells (important for proper immune function).  This is thought to be the reason why supplementing with high amounts of synthetic folic acid can increase the risk of developing cancer (especially colon cancer) (1).  

“if intakes of folic acid are high enough, the symptoms of a B12 deficiency will ‘disappear’”

Another risk associated with a high intake of folic acid, is its ability to hide a B12 deficiency.  The symptoms of low B12 and low folate are so similar, that they are often confused as one another, and if intakes of folic acid are high enough, the symptoms of a B12 deficiency will ‘disappear’.  

Unfortunately, in this case, just because the symptoms are gone, doesn’t mean the deficiency is corrected, and there may be severe nervous system damage developing behind the scenes that can go undetected for years.

Since so many of the foods the typical person consumes these days are fortified with folic acid, it can be quite easy to overdo it, especially if you are taking a multivitamin as well.

These risks that are associated with folic acid are not of concern with naturally occurring folate in foods. 

As with all nutrients, the synthetic version is just not the same as the natural form found in food.  There are likely many co-factor vitamins and nutrients that accompany it in food that are vital to the utilization of this nutrient in our bodies.  And, as mentioned earlier, synthetic folic acid does not cross the placenta – only folate does.  

So in my opinion, even though folic acid does seem to offer some protection against neural tube defects in fetuses, the benefits do not outweigh the risks, especially when we have folate as an option.

How do we make sure we are getting enough folate?

Folate is found in abundance in leafy green vegetables like romaine lettuce, beet greens, turnip greens, spinach, parsley and collards, as well as asparagus, broccoli and cauliflower.  And of course, my favourite superfood: liver is an amazing source of folate!

If you are planning a pregnancy in the next year or so, or if you are pregnant right now (yay!), you will also want to supplement with folate as the required amount for pregnancy is not easy to obtain from diet alone.  In this case, look for a supplement that has the right kind of folate: 5-methyltetrahydrofolate is what you want, and is available in high quality multivitamins and some prenatal formulas.  Be sure to read the label of any supplement you buy.