When patients show me their supplement list, I sometimes see “folic acid” or “cyanocobalamin” tucked in there. These are two of the most common—and cheapest—forms of B vitamins used in supplements. But here’s the problem: they’re also the least effective and can even work against you, especially if you’re dealing with chronic illness.
Why Folic Acid Is a Problem
Folic acid isn’t just an “inferior” version of folate—it can actively get in the way. Because it’s synthetic, your body has to convert it into usable forms, and that process is notoriously inefficient, especially for people with MTHFR variants. Unmetabolized folic acid can build up, block folate receptors, and interfere with the very pathways it’s supposed to support—methylation, detoxification, and neurotransmitter balance.
This may also explain why some patients report being able to tolerate bread, pasta, and baked goods in Europe but not in the U.S. In much of Europe, folic acid fortification is not standard, while here it’s added to most conventional flour products. In other words, it might not be the wheat alone causing trouble—it may be the folic acid riding along with it. For patients with chronic illness, recommending a folic acid–free diet may be just as important as avoiding gluten itself. Organic flours and pastas generally skip the folic acid fortification, which makes them a cleaner choice.
Why Cyanocobalamin Falls Short
Cyanocobalamin is the synthetic form of vitamin B12, and like folic acid, it requires several conversion steps before your body can actually use it. In people with genetic variations, inflammation, or chronic illness, those conversion steps are often sluggish or blocked. What’s worse, cyanocobalamin contains a cyanide molecule—tiny amounts, but still something your body has to detoxify.
The Better Options
Fortunately, we have better choices.
- B12: Methylcobalamin, adenosylcobalamin, and hydroxocobalamin are all bioavailable forms that your body can put to work right away.
- Folate: Methylfolate gets a lot of attention (and rightfully so), but folinic acid may be even more universally beneficial. Folinic acid bypasses many genetic blocks, supports neurotransmitter balance, and is less likely than methylfolate to cause overstimulation or mood swings.
In my experience—and supported by emerging research—folinic acid deserves a central place in supplement protocols for chronic illness.
Final Thoughts
Choosing supplements with bioavailable forms of B12 and folate—such as methylcobalamin, adenosylcobalamin, hydroxocobalamin, and especially folinic acid—gives your body the nutrients it can actually use. These small but important shifts can support detoxification, energy production, and inflammation balance in a way synthetic forms simply cannot.
Sometimes the most overlooked details—like the form of a vitamin—end up being the keys that unlock real healing.
References
- Bailey, S. W., & Ayling, J. E. (2009). The extremely slow and variable activity of dihydrofolate reductase in human liver and its implications for high folic acid intake. PNAS, 106(36), 15424–15429.
- Lucock, M. (2000). Folic acid: nutritional biochemistry, molecular biology, and role in disease processes. Molecular Genetics and Metabolism, 71(1–2), 121–138.
- Shane, B. (2011). Folate chemistry and metabolism. In Folate in Health and Disease (2nd ed., pp. 1–24). CRC Press.
- Obeid, R., & Herrmann, W. (2005). Mechanisms of homocysteine neurotoxicity in neurodegenerative diseases with special reference to dementia. FEBS Letters, 579(2), 291–298.
- Pawlak, R., Lester, S. E., & Babatunde, T. (2016). The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. European Journal of Clinical Nutrition, 70, 866–873.
- Venn, B. J., & Mann, J. I. (2017). Folate, vitamin B12 and health outcomes. Public Health Nutrition, 20(16), 3047–3052.
- Allen, L. H. (2008). Causes of vitamin B12 and folate deficiency. Food and Nutrition Bulletin, 29(2_suppl1), S20–S34.