Vitamin B9 (Folate; 5-MTHF)
Overview
Vitamin B9, commonly known as folate, is a water-soluble vitamin that plays a central role in one-carbon metabolism and methylation processes. The active form, 5-MTHF (5-methyltetrahydrofolate), is an essential cofactor in the remethylation of homocysteine to methionine, which is then converted to S-adenosylmethionine (SAMe). SAMe fuels the synthesis of dopamine, norepinephrine, and serotonin and drives phospholipid methylation in neuronal membranes. Folate works synergistically with other B vitamins (B6, B2, B12) and minerals (zinc) in methylation processes, and deficiencies in these nutrients are correlated with ADHD symptoms.
Recipes
5 recipes containing this substance
Chocolate Quinoa Crisp Clusters
A delicious cereal-to-snack hybrid with satisfying crunch, steady energy, and a low glycemic profile. Perfect for breakfast or anytime snacking.
Matcha Mitochondria Smoothie
Mitochondrial energising smoothie rich in polyphenols, magnesium, and antioxidants
Mitochondrial Power Bowl
A nitrate-rich, polyphenol-dense bowl supporting mitochondrial function, ATP generation, and metabolic resilience
Rocket Lentil Avocado Midday Salad (Gut-Supporting)
Polyphenol-rich salad supporting SIRT1 activation and microbiome synchronisation
Turmeric Lentil Dahl
Anti-inflammatory curcumin-rich lentil dish supporting gut health, NF-κB inhibition, and SCFA production
Foods
23 foods containing this substance
Asparagus
FOS prebiotic fiber and folate source
Black Beans
Legume with polyphenols and protein; optimal soaking conditions detailed
Broccoli
Cruciferous vegetable rich in sulforaphane, folate, and glutathione precursors
Brussels Sprouts
Sulfur compounds for glutathione synthesis
Cabbage
Base for sauerkraut; fiber and vitamin C
Cauliflower
Cruciferous vegetable with fiber and B vitamins
Chickpeas
Legume providing protein, fiber, folate, magnesium, and B6
Edamame
Young soybeans providing NMN (NAD+ precursor) and complete plant protein
Eggs
Complete protein with choline, B vitamins, and phospholipids
Kale
Leafy green rich in iron, magnesium, zinc, quercetin, and carotenoids
Kidney Beans
Polyphenol-rich legume supporting gut health
Lentils
Legume rich in protein, fiber, folate, iron, and prebiotics
Liver
Nutrient-dense organ meat with bioavailable B12, retinol, iron, and CoQ10
Oranges
Vitamin C for iron absorption enhancement
Parsley
Reduces harmful cholesterol oxidation products when added to cooking
Peanuts
Niacin, resveratrol, and plant protein for NAD+ and mitochondrial support
Peas
Plant protein, fiber, and thiamine source
Quinoa
Pseudograin with complete protein, magnesium, and GABA potential in sourdough
Raspberries
Polyphenol-rich berries with fiber
Soy
Complete plant protein with isoflavones (genistein) and choline
Spinach
Leafy green rich in iron, magnesium, folate, and carotenoids
Strawberries
Polyphenol-rich berries supporting cognitive function
Swiss Chard
Leafy green rich in iron, magnesium, folate, and carotenoids
Biological Mechanisms and Implications
| Biological Target | Therapeutic Areas | Mechanism of Action |
|---|---|---|
| Methylation | Essential cofactor in remethylation of homocysteine to methionine, which is converted to S-adenosylmethionine (SAMe); SAMe fuels synthesis of dopamine, norepinephrine, and serotonin and drives phospholipid methylation in neuronal membranes | |
| Neurochemical Balance | Supports neurotransmitter synthesis through methylation; cofactor for dopamine synthesis alongside iron, B6, and omega-3s |
References
- Methylation is a fundamental biochemical process playing a pivotal role in neurotransmitter synthesis, phospholipid metabolism, and gene expression; nutrient-dependent methylation supports recycling of homocysteine into methionine
- B vitamins, particularly B6, B2, folate (5-MTHF), and B12, are essential cofactors in remethylation of homocysteine to methionine, which is converted to SAMe
- Folic acid supplementation (0.5-5 mg/day) typically reduces plasma homocysteine by ~25%; adding B12 gives an additional ~7% reduction Collaboration 1998
- While folate is normally considered the primary nutrient for homocysteine reduction, long-chain omega-3 fatty acids and vitamin B12 also contribute meaningfully; B12+fish oil lowered plasma homocysteine by 39% Tao Huang et al. 2015
- B vitamin supplementation slowed cognitive decline only in participants with adequate omega-3 status, supporting a nutrient synergy model Oulhaj et al. 2016
- Elevated plasma homocysteine is frequently elevated in ADHD and other neurodegenerative disorders Yu et al. 2020
- Homocysteine is implicated in the induction of oxidative stress, modulation of oxygen levels, and initiation of lipid peroxidation pathway Lukovac et al. 2024
- MTHFR polymorphisms reduce the efficiency of folate cycling and methylation, increasing susceptibility to cognitive dysfunction and ADHD-related symptoms
- Research indicates that deficiencies in vitamins and minerals essential for methylation, such as folate, vitamin B12, and zinc, are correlated to ADHD symptoms Razavinia et al. 2024
- Dietary patterns rich in fibre, folate, and omega-3 fatty acids were associated with reduced ADHD symptoms Millichap and Yee 2012
- Isoquercetin bioavailability is improved by simultaneous ingestion with vitamin C, folate, and additional flavonoids Y. Li et al. 2016