Vitamins & Minerals

Folate (Vitamin B9)

Folate (vitamin B9) is a water-soluble B vitamin essential for DNA synthesis, methylation, and red blood cell formation. Serum folate reflects recent dietary intake (1-3 weeks), while red blood cell folate reflects longer-term status (3-4 months). Folate works synergistically with vitamin B12 — deficiency in either can cause megaloblastic anaemia.

Optimal Ranges

Clinical (NHS) Range

>7 nmol/L

nmol/L

Performance-Optimised Range

20-45 nmol/L

nmol/L

The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best.

Why It Matters

Why Folate matters for performance

Folate is critical for methylation — the biochemical process that regulates gene expression, neurotransmitter production, and homocysteine metabolism. Low folate drives up homocysteine, an independent cardiovascular risk factor. For active men, folate supports nitric oxide production (affecting blood flow and exercise performance) and is essential for DNA repair after training-induced cellular stress. The MTHFR gene variant (carried by ~40% of the population) impairs folate conversion, making some men particularly vulnerable to deficiency even with adequate dietary intake.

Symptoms

Signs your levels may be off

Low / Deficiency

  • Fatigue and weakness
  • Brain fog and poor concentration
  • Mouth ulcers and sore tongue
  • Irritability and low mood
  • Shortness of breath

High / Excess

  • May mask B12 deficiency symptoms
  • High doses (>1mg) can interfere with certain medications

Dietary Sources

Foods that support Folate levels

Dark leafy greens — spinach, kale, broccoliLiver (highest natural source)Legumes — lentils, chickpeas, black beansAsparagus and Brussels sproutsFortified cereals and bread (UK mandatory fortification pending)

Supplementation

Evidence-based supplementation

Methylfolate (5-MTHF) is the preferred supplemental form as it bypasses the MTHFR conversion step, making it effective regardless of genetic variant. Standard dose is 400-800mcg daily; those with confirmed MTHFR variants or elevated homocysteine may benefit from 1-5mg under medical guidance. Always take alongside B12 — folate supplementation alone can mask B12 deficiency. Folic acid (the synthetic form) is cheaper but requires enzymatic conversion and may be less effective in MTHFR carriers.

Research

Key study

Folate and disease prevention

Stover PJ, Field MS

The American Journal of Clinical Nutrition (2022)

DOI: 10.1093/ajcn/nqab431

Related Biomarkers

Vitamins & Minerals

Vitamin B12 (Cobalamin)

Optimal: 500-800 pg/mL

Vitamins & Minerals

Iron (Serum Iron, TIBC & Transferrin Saturation)

Optimal: 15-25 µmol/L (serum iron), 20-45% transferrin sat.

Inflammation

Ferritin (Iron Stores)

Optimal: 80-150 ng/mL

Related Guides

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8 biomarkers behind fatigue

Complete Guide to Blood Tests

What to test and why it matters

Test your Folate levels

Folate is included in the Helvy 50+ biomarker panel. Get your results in 5 days with a personalised protocol.

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This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.