Folate is a basic B vitamin (B9) and you should know at least a little about it so you can properly read labels. The big problem is that folate and folic acid are used interchangeably, but they aren’t the same thing. This liberal use of folate to mean folic acid is not appropriate and confusing.
The short takeaway is to choose high-folate foods like spinach, lettuce, and avocados, and if possible, choose supplements that use methyl folate instead of folic acid.
One problem comes from common chemicals that can exist in an acid or base form. Examples are citric acid and citrate, ascorbic acid and ascorbate, carbonic acid and carbonate. You can get the effects of vitamin C by taking ascorbic acid or ascorbate, for example.
The names folate and folic acid do not follow the same convention and are NOT just acid/base forms of the same thing. They should not be used synonymously and they are not processed the same in your body. This is another way of saying that your body has the last word in whether these are synonymous or not, and they are not. Don’t refer to the Wiki page on folate as they will leave you as fully confused.
Let’s review basic vitamin B9 as folate basics:
B9 is important for many reasons. For example, it keeps your homocysteine in a healthy range. Controlled homocysteine levels are important to lower the risk of heart disease and stroke. Normal B9 levels help prevent neural tube defects in the fetus. Normal B9 levels help improve your resistance to several types of cancer.
Because B9 has been recognized as being an essential nutrient, many countries have mandated that certain foods be fortified with B9, but too often supplements and fortified foods contain folic acid, not folate.
Folate is the naturally occurring form of vitamin B9. Common sources are leafy vegetables, hence the Latin name for leaf, “folium,” which gives us the name “folate.” The active form of folate is levomefolic acid, or 5-methyltetrahydrofolate (5-MTHF).
The majority of dietary folate is converted into 5-MTHF before entering the bloodstream.
Folic acid is a synthetic form of B9 and is also known as pteroylmonoglutamic acid. Folic acid is most commonly added to cheaper supplements, flour, and breakfast cereals. Unlike folate, the majority of folic acid is not converted to the active form of B9 (5-MTHF) in the digestive system. It can still be converted to the active form, but this will happen in the liver or other tissues. The problem is this conversion outside the digestive system is that it is slow and inefficient. Un-metabolized folic acid can be found in blood tests of even fasting people.
It matters that folic acid is found in the blood because folic acid is not benign. Some studies have suggested that this un-metabolized folic acid can increase risk of some cancers. High folic acid can also make it more difficult to detect a B12 deficiency, and we now know that low B12 is a major contributor to dementia and impaired nerve function.
To get your B9, look for high-folate foods like asparagus, avocados, Brussels sprouts, and leafy greens such as spinach and lettuce.
Supplementation is smart for people like pregnant women. Look for supplements that list folate or 5-MTHF. Watch for deceptive labeling that might say “folate” (as folic acid).
You might also see 5-MTHF as methyl folate or levomefolate calcium, and these are okay. Some brand names for 5-MTHF are Metafolin and Deplin.
The takeaway: choose a diet high in leafy vegetables, avocados, and supplements that list some form of folate like methyl folate or 5-MTHF and avoid folic acid if you can.