Folate vs Folic Acid - Why Dogs Deserve the Real Thing

When it comes to nutrition, not all vitamins are created equal. Folate and folic acid are often treated as interchangeable, but biologically, they are very different. For dogs, that difference matters more than most people realise.

Folate is vitamin B9 in its natural form. It’s found in whole foods, particularly organ meats like liver. Folic acid, on the other hand, is a synthetic, lab-made version that exists purely because it’s cheap, stable, and easy to add to ultra-processed foods.

The problem is that dogs don’t use these two forms the same way.

Folate From Food vs Folate From Plants

Folate from organ meats, especially liver, is far more bioavailable than folate from plant sources like spinach or leafy greens. This comes down to chemistry.

Plant foods contain folate primarily in a polyglutamate form. Before a dog can absorb it, that folate has to be enzymatically trimmed down in the gut. This extra step reduces how much actually makes it into the bloodstream.

Organ meats, by contrast, contain folate mostly in monoglutamate forms or as 5-methyltetrahydrofolate (5-MTHF). These forms are already prepared for absorption. Because of this, folate from organ meats is typically 70–100% bioavailable, compared to roughly 40–50% from plant sources.

Simply put, dogs get far more usable folate from liver than from greens.

Why Folate Matters So Much

Folate plays a foundational role in the body. It is essential for DNA and RNA synthesis, which makes it critical for cell division, growth, and tissue renewal. It supports red blood cell formation and helps prevent anaemia. It is also central to methylation, a process that affects gene expression, detoxification pathways, and neurotransmitter balance.

Dogs cannot synthesise folate on their own. They rely entirely on dietary intake, which means the source and form of folate matters enormously. A diet that looks adequate on paper can still leave a dog functionally deficient if the folate provided isn’t bioavailable.

Folate During Pregnancy and Development

Folate demand increases dramatically during pregnancy. In pregnant bitches, folate supports rapid cell division in developing embryos, helps prevent neural tube defects affecting the brain and spinal cord, and plays a role in placental formation and normal foetal growth.

Low folate levels during pregnancy have been associated with smaller litter sizes, reduced foetal survival, and developmental abnormalities, particularly involving the nervous system.

This is why highly bioavailable folate, such as that found in liver or methylated forms like 5-MTHF, is far superior to relying on plant-based sources or synthetic additives.

Other Times Folate Demand Increases

Folate needs aren’t static. Demand rises during growth and puppyhood, throughout lactation, during recovery from illness or surgery, and in dogs with high metabolic output such as working or performance dogs.

During these times, relying on poorly absorbed or synthetic forms of folate places unnecessary strain on the body.

The Problem With Synthetic Folic Acid

Folic acid is an oxidised, synthetic form of vitamin B9. It’s widely used in kibble, treats, and fortified foods because it is cheap and extremely stable. But stability doesn’t equal suitability.

Before folic acid can be used by the body, it must be converted into the active form, 5-MTHF. This conversion requires multiple enzymatic steps, with a key role played by the MTHFR enzyme.

Dogs, like humans, vary in how efficiently this enzyme works. When MTHFR activity is reduced due to genetics, inflammation, liver stress, or nutrient deficiencies, folic acid conversion slows or stalls.

When Conversion Breaks Down

When folic acid isn’t efficiently converted, it can accumulate in the bloodstream as unmetabolised folic acid (UMFA). This creates a biochemical traffic jam.

UMFA can block folate receptors, preventing natural folate from being used properly. This can mimic a folate deficiency even when intake appears adequate on paper.

Research in both humans and animals suggests that excess UMFA may disrupt methylation pathways, alter gene expression, suppress immune function, and mask or worsen vitamin B12 deficiency, potentially contributing to neurological issues.

In dogs, this may contribute to weakened immunity, impaired detoxification, and long-term metabolic stress.

Folate Works in a Team

Folate does not work alone. It partners closely with vitamin B12 to convert homocysteine into methionine, a key process in methylation. Other important cofactors include vitamin B6, riboflavin (B2), choline, vitamin C, and zinc.

Whole foods naturally provide these cofactors in balance. Synthetic vitamins do not. This is why isolated, lab-made nutrients often underperform compared to food-based nutrition.

The Takeaway

This is why I choose to avoid feeding anything that contains synthetic folic acid. It’s used extensively in commercial foods because it ticks a formulation b

ox cheaply, not because it supports optimal biology.

Whole foods, particularly organ meats, provide folate in forms dogs can actually use, along with the cofactors that make it work properly.

Feed real food. Biology always responds better to the real thing.