VCVITAMINS/CHART

The Bottom Line

Yes, you can safely take vitamin B9 (folate, folic acid, methylfolate) and flaxseed oil (ALA) together. They work through different body systems and have no known interactions.

VERDICT

Vitamin B9 (folate, folic acid, methylfolate) and flaxseed oil (ALA) are safe together. Because Vitamin B9 is water-soluble and flaxseed oil is fat-soluble, they follow different absorption pathways in the body and no negative interaction has been reported. You can take them at the same time or at any time that fits your routine.

Safe to combine Strong evidence
01 / MECHANISM

How They Interact

Folate, folic acid, and methylfolate are all water-soluble forms of vitamin B9. In the jejunum, folic acid is reduced by dihydrofolate reductase and then methylated, while methylfolate can be absorbed via the reduced folate carrier without needing the MTHFR enzyme. Flaxseed oil contains alpha-linolenic acid (ALA), an omega-3 fatty acid that is fat-soluble. After ingestion, ALA is emulsified by bile salts and incorporated into micelles, then absorbed by enterocytes and packaged into chylomicrons that enter the lymphatic system before reaching the bloodstream. These intestinal transport systems are entirely distinct: folate transporters are ion-coupled integral membrane proteins, while lipid absorption depends on micellar solubilization and fatty acid transporters. There is no shared cofactor, common enzyme, or cytochrome P450-mediated pathway that would allow these two compounds to interact. Flaxseed oil does not alter gastric pH or gastrointestinal transit time enough to change folate absorption, and vitamin B9 has no effect on fat digestion or omega-3 metabolism. For these reasons, the two supplements are biologically silent when taken together.

02 / BEST PRACTICES

How To Take Them

If you need both, the simplest approach is to take them together in the morning with breakfast. A breakfast containing a little healthy fat will help your body absorb the ALA, while the water-soluble folate can be taken with water or juice at the same meal. No spacing is required. If you miss a dose, just take it with your next meal, but do not double up on either supplement. For the most reliable absorption of folate, especially if you have MTHFR variants, choose methylfolate, while for flaxseed oil, keep the bottle refrigerated after opening and respect the expiration date.

03 / FORM MATTERS

Form & Quality Differences

The most common forms of vitamin B9 are folic acid, the synthetic form in fortified foods and inexpensive supplements, and methylfolate (L-5-MTHF), the active form that is used directly by the body. If you have a common MTHFR polymorphism, methylfolate may be a more effective choice, but this does not change how it interacts with flaxseed oil. Flaxseed oil is available as liquid oil, softgel capsules, and as ground flaxseed meal, which also contains fiber and lignans. The ALA in softgels is stable and convenient, while liquid oil can be added to salads or yogurt; no matter which form you use, you can still take it alongside your B9 supplement.

04 / COMMON STACKS

Where This Pair Shows Up

These two supplements are frequently paired in plant-based prenatal vitamins, where methylfolate is combined with flaxseed oil as a source of omega-3 fatty acids, and in general heart-health supplements that combine a B-complex with ALA oil.

Multivitamins Prenatals Performance Longevity
05

Practical Tips

06

Frequently Asked Questions

Who Should Be Careful No specific caution applies to combining vitamin B9 and flaxseed oil. However, flaxseed oil in high doses may have a mild anticoagulant effect, so people taking warfarin or other blood thinners should talk to their healthcare provider before consuming large amounts. High doses of folic acid can mask a vitamin B12 deficiency, which is especially important for older adults and strict vegetarians; ensure your B12 status is monitored. Pregnant and breastfeeding people should follow prenatal supplement recommendations from their care team.
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Sources & Further Reading

  1. NIH ODS NIH Office of Dietary Supplements — Vitamin B9 Fact Sheet
  2. NIH ODS NIH Office of Dietary Supplements — Flaxseed Oil Fact Sheet
  3. Examine.com Examine.com — Folate interaction page
  4. Examine.com Examine.com — Alpha-linolenic acid interaction page

Reviewed by Caroline M. on April 23, 2026 for accuracy against the sources listed above. This page is educational and is not a substitute for professional medical advice.

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Back To The Vitamins Chart All Flaxseed Oil (ALA) Interactions All Vitamin B9 (Folate, Folic Acid, Methylfolate) Interactions