Re-printing from https://chriskresser.com/folate-vs-folic-acid/

If I asked you which of these vitamins was found naturally in food, folate or folic acid, would you know the answer? If not, you’re in good company. Medical professionals, nutrition experts, and health practitioners frequently mix up the two, simply because the terms are often used interchangeably.

Many health professionals would even argue that folate and folic acid are essentially the same nutrient. While folic acid is often considered to be a supplemental form of folate, there is an important distinction between these two different compounds. For women past childbearing age, and for men in general, excessive doses of the synthetic form of this nutrient are not necessary, and may even be harmful.

What’s the difference between folate and folic acid?

Folate is a general term for a group of water soluble b-vitamins, and is also known as B9. Folic acid refers to the oxidized synthetic compound used in dietary supplements and food fortification, whereas folate refers to the various tetrahydrofolate derivatives naturally found in food.

The form of folate that can enter the main folate metabolic cycle is tetrahydrofolate (THF). (2) Unlike natural folates, which are metabolized to THF in the mucosa of the small intestine, folic acid undergoes initial reduction and methylation in the liver, where conversion to the THF form requires dihydrofolate reductase.The low activity of this enzyme in the human liver, combined with a high intake of folic acid, may result in unnatural levels of unmetabolized folic acid entering the systemic circulation.

Several studies have reported the presence of unmetabolized folic acid in the blood following the consumption of folic acid supplements or fortified foods. (3) Human exposure to folic acid was non-existent until its chemical synthesis in 1943, and was introduced as a mandatory food fortification in 1998. (4) Food fortification was deemed mandatory due to overwhelming evidence for the protective effect of folic acid supplementation before conception and during early pregnancy on the development of neural tube defects (NTD) in newborns.

Risks associated with excessive folic acid intake

While the incidence of NTDs in the United States been significantly reduced since folic acid fortification began, there has been concern about the safety of chronic intake of high levels of folic acid from fortified foods, beverages and dietary supplements. (5) One of the major risks associated with excessive intake of folic acid is the development of cancer. (6) In patients with ischemic heart disease in Norway, where there is no folic acid fortification of foods, treatment with folic acid plus vitamin B12 was associated with increased cancer outcomes and all-cause mortality. In the United States, Canada, and Chile, the institution of a folic acid supplementation program was associated with an increased prevalence of colon cancer. (7, 8) A randomized control trial found that that daily supplementation with 1 mg of folic acid was associated with an increased risk of prostate cancer. (9)

Researchers have hypothesized that the excessive consumption of folic acid in fortified foods may be directly related to the increase in cancer rates. Excess folic acid may stimulate the growth of established neoplasms, which can eventually lead to cancer. The presence of unmetabolized folic acid in the blood is associated with decreased natural killer cytotoxicity. (10) Since natural killer cells play a role in tumor cell destruction, this would suggest another way in which excess folic acid might promote existing premalignant and malignant lesions.A high intake of folic acid might mask detection of vitamin B12 deficiency and lead to a deterioration of central nervous system function in the elderly.

In one study, consumption of folic acid in excess of 400 micrograms per day among older adults resulted in significantly faster rate of cognitive decline than supplement nonusers. (11) Another study found a higher prevalence of both anemia and cognitive impairment in association with high folic acid intake in older adults with a low vitamin B12 status. (12) As vitamin B12 deficiency is a common problem for many older adults, these studies suggest that high folic acid intake could cause serious cognitive consequences in the elderly.

Folate from natural food sources is best

Despite the risks associated with high levels of folic acid intake, it is well established that adequate folate intake from the consumption of folate-rich foods is essential for health.

Folate aids the complete development of red blood cells, reduces levels of homocysteine in the blood, and supports nervous system function. It is well known for its role in preventing neural tube defects in newborns, so women of childbearing age must be sure to have an adequate intake prior to and during pregnancy.

Excellent sources of dietary folate include vegetables such as romaine lettuce, spinach, asparagus, turnip greens, mustard greens, parsley, collard greens, broccoli, cauliflower, beets, and lentils. (13) Not surprisingly, some of the best food sources of folate are calf’s liver and chicken liver.

You can supplement with folate if your dietary intake is inadequate. Look for products that contain the Metfolin brand, or list “5-methyltetrahydrofolate” or “5-MTHF” on the label. Avoid products that say “folic acid” on the label. Make sure to check your multivitamin, because most multis contain folic acid and not folate.

Women planning on becoming pregnant should consume between 800 and 1200 mcg of folate per day for several months before the start of pregnancy. Unless you’re consuming chicken or calf’s liver and substantial amounts of leafy greens on a regular basis, it’s difficult to obtain this amount from diet alone. If you’re pregnant or trying to get pregnant, I recommend supplementing with 600-800 mcg of folate per day, depending on your dietary intake. Solgaris a good brand, but there are several others that typically use 5-MTHF including Designs for Health, Thorne, Metabolic Maintenance and Pure Encapsulations.

All other people, such as men and older women, should be able to get plenty of folate in a diet with adequate vegetable consumption, and do not need to supplement.

True healing is achieved by our entire self. Each part of our self is important and each part contributes to the whole of being well. When I say each part I am referring to all of the things that make up the whole of who we are. Our relationships, our creative life, our work life, our spiritual life and our relationship with our body. Since I am talking about food here I am going to focus a little more on the body but it would be incorrect to say that food is only about the body. It is really deeply connected to all the other parts of us as well.

Food and the nourishment that it gives is one of the foundation pieces of vibrant health. When we eat we are bringing into our body the necessary components for all the millions of chemical processes that our physical body runs on. An example of this is getting adequate protein. Proteins are the source of amino acids which in turn are the building blocks of some of the thousands of different substances needed to run a human body. They are an essential part of running our detox pathways, and insure that we have adequate neurotransmitters or brain chemicals. This is just one example out of millions of processes that happen daily, even hourly in our body that are dependent on our having the macro and micro nutrients the we get from eating high quality food.

The foundations of a diet that supports and builds excellent health begins with eating organic food free of toxic chemicals, lots of vegetables and adequate protein and fats. This is a great place to start a delicious relationship with food. But what about the fact that each of us is different. Its true, each of us is different and we each have our own particular nutritional quirks and needs. Often there are acute situations that need to be addressed with an individually crafted diet and sometimes there are foods that an individual just doesn’t do well with for the long haul. This takes some work and guidance to figure out.

There’s more. Food isn’t all about balancing protein carbs and fats. There is the pleasure aspect of food, how it tastes, the enjoyment and creativity of cooking and sharing a meal and conversation with your people. Then there is the absolute beauty of a well grown head of Romanesco Broccoli. The benefits of relating to food in this way are real and have a measurable impact on our whole being. So excellent nutrition and an alive relationship to food in all its aspects is one of the real foundations and bedrocks of glowing good health.