Vitamin B9, Folates, not Folic Acid Know the difference as it will impact your health! B9, Folate also known as Folinic acid is important for fertility and when cells and tissues are growing rapidly; infancy, adolescence, and pregnancy. It is crucial for brain function and plays an important role in mental health. It helps our genes and works closely with vitamin B12, B6 and other nutrients for heart health. Most food contains B9; Seafood, meats, especially liver, green leafy veg, beans etc. It should not be confused with Folic acid which is the synthetic form. This form is not easily absorbed by the body. Unfortunately, synthetic folic acid is being mandated into the white wheat flour in the UK food chain from December 2026. However, it has already started and we are seeing it, even in wholemeal products, notably Marks & Spencer bread. It is in soups, check your Heinz labels, sauces, pastas, frozen chips and so much more. Get yourself a food scanning app like

So why is synthetic folic acid such and issue. Lets look at some of the side effects. 1. Suppresses Immunity: Unmetabolized Folic Acid (UMFA) AccumulationConsuming more than 200–400 mcg floods the liver's slow conversion enzymes, causing raw, synthetic vitamin fragments to circulate freely in the blood. This can temporarily suppress natural killer (NK) immune cells. 2. Blocks Absorption of Folate: Excess synthetic folic acid binds up to 10 times more tightly to Folate Receptor Alpha (FRα) than natural folate, physically blocking your cells from absorbing the active, bioavailable folate they actually need. 3. Masks B12 Deficiency can cause nerve damage and cognitive decline if undetected. High doses correct the red blood cell changes caused by a Vitamin B12 deficiency, hiding it on standard blood tests. 4. Gastrointestinal Distress from high daily intake (above 1,000 mcg) frequently cause nausea, bloating, abdominal cramping, severe gas, and a persistent bitter taste in the mouth. 5. Neurological Disruptions can trigger sleep disturbances, vivid dreams, over-excitation, irritability, and difficulty concentrating. 6. Epigenetic Alterations from excess exposure in utero may lead to cellular over-methylation, which child health studies have linked to a higher risk of childhood asthma and allergies.

Who Should Avoid Synthetic Folic Acid?

Some groups of people need to avoid it due to biochemical risks and should prioritize unfortified whole foods alongside pre-activated, natural folate alternatives (like L-Methylfolate or Folinic Acid):

1. People with Coronary Stents or Recent Angioplasty. Clinical trials (like the NORVIT and WENBIT studies) found that high doses of folic acid significantly increased the rate of re-stenosis (the re-clogging of the artery inside the stent). Folic acid drives rapid cell division, which can accidentally accelerate smooth muscle tissue overgrowth around the surgical mesh, narrowing the artery again.
2. Individuals with MTHFR Genetic Variations (up to 50% of the population) lack the enzyme needed to convert synthetic folic acid into its usable form. The synthetic version clogs up their cellular receptors, worsening a functional folate deficiency while showing deceptively high folate levels on blood tests.
3. Developing Fetuses and Pregnant Women (Late Pregnancy) should avoid as immature fetal livers completely lack the capacity to break down synthetic molecules, causing synthetic UMFA to accumulate directly in fetal tissues and cord blood. Furthermore, excessive synthetic intake late in pregnancy can trigger over-methylation, affecting long-term childhood development.
4. Young Children (Ages 1 to 8) should avoid it as children have a very low tolerable level (300–400 mcg). Their smaller livers cannot efficiently process synthetic additives. Eating a modern diet of "double-fortified" commercial breakfast cereals and mandatory fortified white bread quickly pushes them into chronic overdose.
5. Adults with Undiagnosed or Borderline Vitamin B12 Deficiency which can affect older adults, vegans, and people with gut issues (like Crohn's or Celiac disease). This group risks severe, irreversible neurological damage if synthetic folic acid masks their true B12 status.

B vitamins can be found in most food such as leafy greens, eggs, meat, poultry, seafood etc. Make sure that the veg is low in oxalates as high oxalate intake can increase the need for some B vitamins. However, it is important that you look after your friendly gut flora as everything works together like a formula one racing team.