If folic acid is so harmful or “unnatural/toxic,” why have decades of randomised controlled trials and population-level fortification programs (e.g., in the US since 1998) consistently shown dramatic reductions in neural tube defects (like spina bifida and anencephaly) without corresponding widespread epidemics of the harms you claim?
What exact mechanism and high-quality human evidence (not just animal studies or observational correlations) do you have that typical dietary/supplement levels of folic acid cause cancer promotion, immune dysfunction, or other serious issues in the general population—especially when major health authorities (CDC, WHO-affiliated reviews) have reviewed the data and found no confirmed harm at recommended doses?
For people with common MTHFR variants (which affect ~10-40% of populations depending on the specific SNP and ethnicity), why do studies still show that folic acid supplementation effectively raises blood folate levels and helps prevent neural tube defects, even if conversion is somewhat less efficient? And why do experts note that only folic acid has robust trial data for NTD prevention, while methylfolate does not?
If unmetabolized folic acid (UMFA) in the blood is dangerous and builds up especially in those with MTHFR issues, why is it detected in many people even without high supplementation, and why haven’t large-scale post-fortification studies linked it to clear, causal health epidemics (e.g., autism, allergies, cognitive decline) rather than associations that could be confounded by other factors?
How would you ensure adequate folate intake for the entire population—especially women of childbearing age who may not plan pregnancies far in advance—if we stopped fortifying staple foods and relied only on “natural” dietary folate from leafy greens, legumes, etc.? What real-world compliance and equity data support that this would work as well as fortification has?
If high folic acid intake “masks” vitamin B12 deficiency, why is this primarily a concern only at very high doses (thousands of mcg), and why do guidelines simply recommend pairing it with adequate B12 monitoring rather than avoiding folic acid entirely—especially since natural food folates can have similar effects on anaemia symptoms?
Many anti-folic acid arguments cite potential risks like increased twinning, insulin resistance in offspring, or epigenetic changes. But why do controlled studies and systematic reviews often find no statistically significant harms (or attribute them to confounders like IVF), while the benefit for preventing severe birth defects remains clear?
If folic acid is “not bioactive” and methylfolate is always superior, why hasn’t methylfolate (or other reduced folates) replaced folic acid in public health recommendations and fortification programs worldwide, given the need for stability in food processing and proven efficacy in preventing NTDs?
For individuals or populations with low dietary folate intake, what’s your evidence-based plan to prevent neural tube defects and other folate-related issues (e.g., megaloblastic anaemia) without using synthetic folic acid or fortification—especially in regions or socioeconomic groups where access to large amounts of fresh, folate-rich foods is limited or inconsistent?
If you recommend avoiding all fortified foods and folic acid supplements, how do you account for the fact that post-fortification data in many countries show sustained drops in NTD rates with no clear population-level spike in the cancers, cognitive issues, or other problems that lab/animal studies sometimes suggest at supraphysiological doses?