From the other articles on the website I think we can all see that it is very important to have folic acid abundantly in our diets or else use supplementation. I would like to address the various forms of folate or folic acid in our food supply and in our bodies, list some of the best food sources, address problems with losses during food preparation and discuss the benefits of supplementation.

 

Folic acid is found in foods in the form of large molecules. Our intestines can only absorb a smaller form, so enzymes in the intestinal lining break up the folate found in foods.1 The supplemental form of folic acid, found in pills or as fortification to enriched grain products such as breads and cereals is actually easier to absorb.

 

The amount of folate is now measured in DFE’s or Dietary Folate Equivalents to make assessment of consumption more accurate. One microgram of folate in whole foods provides 1 microgram of DFE. One microgram of folic acid supplements taken with meals or as fortified food provides 1.7 micrograms DFE. The highest amount comes from 1 microgram of folic acid supplement taken on an empty stomach. This provides 2 micrograms of DFE. Absorption is best on an empty stomach because there are many foods that inhibit folic acid absorption, even some that are sources of folic acid.3

 

The supplemental form of folic acid, found in pills or as fortification to enriched grain products such as breads and cereals is actually easier to absorb.

 

The term folate came about because the vitamin was first identified in green leafy vegetables or foliage. Greens provide some of the best sources of the vitamin. Unfortunately as much as 50% of the folate in food can be destroyed by heat in meal preparation. The table lists some good food sources taken from Linus Pauling’s web site2 and other sources6, 7. The US RDA for folic acid is 400 micrograms per day for adults, 600 for pregnant women, and 500 for lactating women.2

 

 

The B12 Coverup

 

 

There is concern about the upper limit of how much folic acid a person supplements. A deficiency of either folic acid or vitamin B12 can contribute to megaloblastic anemia . If someone takes enough folic acid, it will remedy the anemia, yet there may still be an underlying B12 deficiency. If the B12 deficiency goes untreated, irreversible nerve damage can occur. 95% of people who are deficient in B12 get plenty of the vitamin in their diet, but are unable to absorb it because they lack intrinsic factor in their stomachs. As long as an adult gets less than one milligram (1000 mcg) of folate there should be no problem with covering up a B12 deficiency.2

 

For midwives who happen to care for women high risk for preeclampsia, early pregnancy loss, or abruption, larger amounts of folic acid would be advisable. Many regimens call for a woman with a history of giving birth to a baby with a neural tube defect to take 4 mg (4000 micrograms) of folic acid a day. It would be safe to do this if she where also getting B12 injections or taking a large dose of B12 such as 500 micrograms daily.4 The RDA for vitamin B12 is 2.0 micrograms per day. Somewhere between 1 and 3% of B12 that is ingested is absorbed directly instead of needing to depend on intrinsic factor.5 So a person taking 500 micrograms per day who lacked intrinsic factor would still absorb between 5 and 15 micrograms and this has been shown to correct B12 deficiency.4

 

Food

Serving Size

Folate
(micrograms)

Fortified Breakfast Cereal

1 cup

200 - 4002

Orange Juice from concentrate

6 ounces

822

Tomato Juice, canned

6 ounces

356

Spinach (cooked)

½ cup

1312

Spinach (raw)

1 cup

606

Turnip Greens, frozen, cooked

½ cup

656

Mustard Greens, frozen, cooked

½ cup

527

Broccoli, chopped, frozen, ckd

½ cup

506

Okra, frozen, sliced, cooked

½ cup

1337

Okra, batter fried from fresh

1 cup

377

Romaine Lettuce, shredded

½ cup

406

Iceberg Lettuce, shredded

½ cup

156

Beets, cooked

½ cup

457

Asparagus (cooked)

½ cup (~6 spears)

1312

Lentils (cooked)

½ cup

1792

Lima Beans (cooked)

½ cup

782

Great Northern beans (cooked)

½ cup

906

Pinto Beans, cooked from dry

½ cup

1477

Navy Beans, cooked from dry

1 cup

2557

Green Peas, cooked

½ cup

506

Enriched Bread

1 slice

202

Pasta (cooked)

1 cup

602

Enriched Rice (cooked)

1 cup

602

Beef Liver (cooked, braised)

3 ounces

1856

Banana

1 med

206

Orange

1 small

306

Cantaloup, raw

1/4 medium

256

Avocado, sliced

½ cup

456

Peanuts, oil roasted

1 ounce

367



 

 

Notes:

 

1. Manuela Fodinger, Walter Horl, and Gere Sunder-Plassmann, (1999) Molecular biology of 5,10-methylenetetrahydofolate reductase Journal of Nephrology JN; Vol 13:00-00.

 

2. http://lpi.oregonstate.edu/

infocenter/vitamins/fa/printfa.html. Linus Pauling Institute’s Micronutrient Information Center, Folic Acid. Last updated 04/08/2002.

3. Recommended Dietary Allowances: 10th Edition (1989)
http://books.nap.edu/books/0309046335/html/151.html

4. Sharabi A., et.al., (2003) Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. British Journal of Clinical Pharmacology Dec;56(6):635-8.

5. Recommended Dietary Allowances: 10th Edition (1989)
http://books.nap.edu/books/0309046335/html/160.html

6. www.websmartideas.com/health

/vitamins/folate-food-sources.html

7. Frances Sizer and Eleanor Whitney, Hamilton and Whitney’s Nutrition: Concepts and Controversies, 6th ed. West Publishing Co. Minneapolis/St. Paul 1994.