Folic acid foods

Which foods contain folate?

The NIH Office of Dietary Supplements lists vegetables (especially dark green leafy ones), fruits and fruit juices, nuts, legumes, seafood, eggs, dairy products, meat, poultry and grains as natural folate sources. Spinach, liver, asparagus and Brussels sprouts are among the foods with the highest folate. ^[1]

Natural folate in foods and folic acid in supplements are not absorbed at the same rate. According to the NIH, about 50% of folate in foods is absorbed, while at least 85% of folic acid taken with a meal is absorbed. For this reason, folate is given in µg DFE in tables and daily values; for food, 1 µg folate = 1 µg DFE. ^[1]

Folate food table

The values below are taken from the selected foods table in the NIH Folate Health Professional fact sheet. Servings and products are US-based (“cup” is the US “cup” measure, about 240 mL; 1 oz ≈ 28 g); the content and serving size of products in Türkiye may differ. Rows marked with a dagger (†) are, according to the NIH, products to which folic acid has been added (fortified).

The table is an order-of-magnitude guide, not a shopping list. The variety of the same food, the way it is cooked and whether it is fortified change the value. For reference, the adult RDA cited by the NIH is 400 µg DFE per day; for example, the 131 µg DFE in ½ cup of boiled spinach corresponds to about one third of this. ^[1]

How do cooking and processing affect folate?

The introduction of Delchier and colleagues reports that folate is sensitive to heat, light, pH and leaching into water. The study tracked where losses occur along industrial processing chains: on the freezing line, the folate content of spinach fell by 25% at the washing stage, and in canned green beans by 30% after sterilization; 20% of the initial amount in green beans had passed into the cover liquid. In both processes the main mechanism was passage into water, and the authors state that limiting the vegetable’s contact with water or steaming is an appropriate measure to reduce loss. ^[3]

In the study by Czarnowska-Kujawska and colleagues, broccoli and spinach were cooked by boiling, steaming, microwave, combi oven and sous-vide. In both vegetables, sous-vide preserved folate vitamers better than boiling; in broccoli, folate loss did not exceed 30% with sous-vide, microwave and combi oven. ^[4] These two studies were conducted under controlled conditions; losses in home kitchens were not measured in them.

Folic acid, on the other hand, is not as sensitive as folate. The CDC reports that folic acid is more stable than food folates and stays stable during cooking or baking, which is why it is used in supplements and fortified foods. ^[2]

How are foods with added folic acid read?

The CDC states that in the US, folic acid is added to products such as bread, pasta, some breakfast cereals and some corn masa flour, and that these products are labeled “enriched”. ^[2] In the NIH table as well, rice, spaghetti and white bread are marked as fortified products.

In a fortified product, the folate amount is read as µg DFE and, if folic acid has been added, additionally as µg folic acid. The NIH’s formula is: µg DFE = natural folate µg + 1.7 × folic acid µg. Accordingly, if a breakfast cereal marked as 100 µg DFE comes entirely from folic acid, this corresponds to about 59 µg of folic acid (100 ÷ 1.7). ^[1]

What is the status of fortified foods in Türkiye?

In the Food Fortification Initiative’s Türkiye profile, fortification legislation for wheat, maize and rice is listed as “None”. This is the database of a civil-society initiative; it is not an official Turkish document. ^[5] A 2020 report in the Türk Halk Sağlığı Dergisi whose title includes “Ministry of Health recommendations” reports that folate intake in women of childbearing age in Türkiye falls below the daily requirement and proposes that regulation be introduced for fortifying flour with iron and folic acid. According to the report, the Ministry’s fortification recommendations had been submitted to the Ministry of Agriculture and Forestry, but no regulation on this had been made as of the date of the report. ^[6]

For this reason, intake data arising under mandatory fortification in the US cannot be carried over directly to Türkiye; the pregnancy recommendation in Türkiye is given on the pregnancy page.

Can too much folate be obtained from food?

The NIH reports that it has not set a tolerable upper intake level (UL) for natural folate in food, because harm from high folate intake from foods has not been reported. The adult limit of 1,000 µg is defined only for folic acid from supplements and fortified foods. ^[1] For this reason, it would not be correct to assess the spinach or legumes on a plate and a supplement in the same way in terms of the “upper limit”.

What affects absorption and level besides food?

Folate status does not depend only on the amount in food. According to the NIH, alcohol impairs folate absorption and retention in the liver, accelerates breakdown and increases urinary excretion; in malabsorption disorders such as celiac disease and inflammatory bowel disease, less folate may be absorbed. ^[1] For this reason, saying “I eat enough folate-rich foods” does not mean an adequate folate level in a particular health condition; the diagnosis of folate deficiency is made with blood measurements.

Can enough folate be obtained from food alone?

The daily reference intake in adults is 400 µg DFE, and the table above shows that this magnitude can be approached with a few servings. The NIH states that in pregnancy the RDA rises from 400 to 600 µg DFE and that reaching this level from food alone may be difficult for some women. ^[1] The folic acid recommendation for women who could become pregnant is a separate recommendation given independently of folate in foods.

This guide does not recommend personal doses.