Folate and Bariatric Surgery

Vitamin B9, known as folate, is crucial for red blood cell formation and healthy cell growth and function. Folate helps form DNA by creating nucleotides. It also helps in protein metabolism by breaking down homocysteine, an amino acid that can cause adverse health effects in high concentrations. This vitamin is water-soluble, meaning excess amounts are excreted in the urine. Water-soluble vitamins are not stored in the body and must be replenished regularly through diet or supplementation. Luckily, folate is naturally present in many foods, so most people eating a well-balanced diet get plenty of folate daily. Foods with folate include beef liver, dark leafy vegetables (think asparagus, brussels sprouts, and spinach), oranges, kidney beans, and peanuts. Some foods contain added folic acids, such as enriched bread, flour, rice, breakfast cereals, and corn flour.

While “folate” and “folic acid” are often used interchangeably, there is a distinct difference. Folate is the naturally occurring form, while folic acid is the synthetic form of B9. This is also known as pteroylmonoglutamic acid. This is often added to processed food products and used in supplements. Folic acid has been added to foods in the US since 1998 when the FDA required it to enrich grain products. This fortification is used to help prevent congenital disabilities in newborns.

Folate and Pregnancy

Vitamin B9 is essential for organ development of a baby in utero. Obtaining enough folic acid can help prevent congenital disabilities, including spina bifida, in which the spinal cord doesn’t form properly. Some research also shows that folic acid supplementation in early pregnancy can help prevent cleft lip and palate. Another side effect of not getting enough folic acid during pregnancy is anencephaly, in which the baby’s brain and skull do not form correctly. Research indicates that fortifying folic acid into processed foods reduces congenital disabilities in about 1,300 babies annually and about 35% overall since 1998. The CDC recommends that women who are pregnant or plan to become pregnant should take 400mcg of folic acid daily.

Folate and Alcohol

People who drink alcohol regularly are at a higher risk for folate deficiency since alcohol impairs its absorption and, therefore, may need up to 600mcg per day to avoid a deficiency. For reference, one cup of cooked spinach contains 263 mcg of folate. Thus, eating a well-balanced diet, including lots of leafy greens, can help ensure adequate intake of folate naturally from food.

Folate Deficiency

Folate deficiency can lead to folate deficiency anemia, where the body doesn’t produce enough healthy red blood cells. This is known as megaloblastic anemia, where the red blood cells are larger than normal but often fewer in number. Because red blood cells are responsible for carrying oxygen around the body, having a folate deficiency can negatively affect every cell in the body.

Folate deficiency anemia can be caused by not eating enough foods with folate or drinking too much alcohol. It also occurs in people with certain diseases of the lower digestive tract, such as celiac disease, if the lower GI cells are damaged and cannot absorb nutrients properly. Folate deficiency symptoms include pale skin, decreased appetite, fatigue, diarrhea, and breathlessness. A simple blood test can easily detect a folate deficiency and treatment typically includes a folic acid supplement and recommendations to increase the intake of folate-rich foods. Supplementing with folate in the recommended dosage is safe and has no known side effects.

Several medications have known interactions with folic acid supplementation. Ask your doctor before taking folic acid if you take birth control, anticonvulsants, methotrexate, or cholesterol-lowering medications.

Folate deficiency is also common after bariatric surgery. According to a recent study, this deficiency occurs in about 65% of bariatric surgery patients. There are a couple of possible reasons for this:

  1. Many experts think this is partially due to the changes in the GI tract that occur with surgery, which can affect the absorption of folate and other nutrients. Bariatric surgery patients may require a supplement of between 400mcg and 800mcg of folic acid per day.
  2. Another cause for folate deficiency after bariatric surgery is due to dietary changes as the surgery works to reduce the amount of food eaten. Because of this, most health experts recommend that patients eat at least three servings of fruits and vegetables per day to ensure adequate nutritional intake.

Remember that the upper limit for folic acid is 1000mg, and bariatric patients should not exceed this amount with supplements unless directed by their physician. This is because too much folate can mask a B12 deficiency, another common problem after bariatric surgery.

A dietitian, doctor, or other health care professional can recommend a supplement that will meet a patient’s needs after surgery.


    1. Folate. Micromedex 2.0 Healthcare Series. http://www.micromedexsolutions.com. Accessed Aug. 9, 2017.
    2. Folic acid (folacin; pteroylglutamic acid; folate) oral. Facts & Comparisons eAnswers. http://www.wolterskluwercdi.com/facts-comparisons-online/. Accessed Aug. 9, 2017.Fairfield KM. Vitamin supplementation in disease prevention.https://www.uptodate.com/contents/search. Accessed Aug. 15, 2017.
    3. Folate: Fact sheet for health professionals. National Institutes of Health Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/. Accessed Oct. 10, 2017.
    4. Kaushansky K, et al., eds. Folate, cobalamin, and megaloblastic anemias. In: Williams Hematology. 9th ed. New York, N.Y.: McGraw-Hill Education; 2016. http://accessmedicine.mhmedical.com. Accessed Aug. 15, 2017.
    5. National Institutes of Health; Eunice Kennedy Shriver National Institute of Child Health and Human Development. Neural Tube Defects (NTDs): Condition Information. Bethesda, MD: USA.gov; Nov 30, 2012. [May 2, 2014]. http://www.nichd.nih.gov/health/topics/ntds/conditioninfo/Pages/default.aspx.
    6. Centers for Disease Control and Prevention (CDC). CDC Grand Rounds: additional opportunities to prevent neural tube defects with folic acid fortification. MMWR Morb Mortal Wkly Rep. 2010 Aug 13;59(31):980–4. [PubMed]

Chloe Seddon is a registered dietitian nutritionist who holds a Master’s Degree in health promotion from the University of Connecticut. She specializes in nutritional counseling, with a focus on a non-dieting approach to maintain healthy weight and goal-oriented lifestyle changes for long term success. She teaches intuitive eating and easy meal preparation to help clients sort through the myriad of nutritional misinformation to focus on having a balanced and happy relationship with food. She counsels clients with a range of issues, including chronic disease management, sports nutrition, disordered eating and weight loss. Chloe currently works as a nutritional counselor and educator providing group and individual consulting. She believes that balancing food, eating and exercise should be enjoyable and healthful.

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