Fooling With Folate Terminology In Pregnancy

Folic Acid Folate

Your doctor telling you to take folic acid is trying to help you, but the nutritional supplement industry too often is more like the Music Man–a 1960s musical about a traveling salesman of musical instruments who cannot read a single note. They want your money, so they go to great effort trying to convince you that this product –which they call natural– is better than some other, more commonly purchased product.

I thought of this after getting a message recently from a friend asking about issues related to possible exposure by her family to toxic metals. It’s a complex scenario, because they are moving between countries, plus one of the kids apparently has a genetic disease where the symptoms could look similar to what happens in mercury poisoning. Somewhere in the discussion, though, she made the point that she was using a particular B vitamin supplement product. It contains ‘natural’ folates, she emphasized, rather than folic acid. She thought that was better, because of numerous articles making that point that she was finding on-line. This tells me that it may be time for a brief chemistry lesion, which I promise to keep it simple and brief.

Everybody needs to have adequate intake of vitamin B-9, which you can call folic acid, or folate. Pregnant women need it in particular, because inadequate levels can lead to what’s called a neural tube defect, where the layers covering the spinal cord or brain do not close.


When it comes to your body, those terms folic acid and folate are interchangeable. It is true that there are differences between formulations of supplemental folic acid/folate. There are different levels of impurities, plus the term ‘folate’ often is used to include not just folate, but certain chemical variations of it.  Furthermore, controversy surrounds whether certain formulations of folic acid are absorbed into the body better than other. This has to do with other chemicals that are bound to the vitamin in the mixture in the pill, but once liberated the only issue is the chemistry of the vitamin itself, which works like this: When you compare folic acid and folate, the only difference is one proton (a hydrogen atom without an electron).

The acid form of the nutrient, folic acid, has a proton attached where base form of the nutrient, folate, does not. The pill that you bought may have been made from folic acid or folate, but when the nutrient dissolves it goes into what’s called equilibrium, where some of it exists in the acidic form (with the extra proton attached) and the rest in the deprotonated form. How much is in each form does not depend on what went into the pill. It depends on the pH and thus where it is in your body. In your stomach, where the pill goes first, pH is very low, causing nearly all of the nutrient to exist as folic acid. Then, in the small intestine, pH rises, so the equilibrium reverses and you’ve got more folate.

The take home message here is don’t worry about choosing one folic acid or folate product over another, based on which is ‘natural’ and which is ‘synthetic’. The laws of chemistry operate the same in the body as they do anywhere else in the universe.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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