BiomarkersFolate (serum)

Vitamins

Folate (serum)

For DNA, red blood cells and early pregnancy

On your report it may say: Serum folate, Folic acid

Folate is a B vitamin needed to make DNA and red blood cells, and it is critical in early pregnancy. Serum folate reflects recent intake; RBC folate shows longer-term status.

Updated 2026-10-26

Typical ranges · ng/mL

Deficient below 3
Possibly low 3–6
In range 6–20
High 20+

nmol/L = ng/mL × 2.266

Always read folate alongside B12, because folate can hide a B12 deficiency.

Ranges vary by lab, age and sex. The range printed on your report applies.

If it's low

Recent folate intake has been low, which can lead to anaemia and raises risks in early pregnancy.

Common causes

  • Few leafy greens, pulses or fruit
  • Heavy alcohol use
  • Pregnancy
  • Some medicines (methotrexate, certain anti-seizure drugs)
  • Gut absorption problems

What you might notice

  • Tiredness
  • Pale skin
  • Mouth ulcers or sore tongue
  • Irritability

If it's high

High folate usually means supplements or fortified foods. It's not harmful itself but can mask low B12.

Common causes

  • Folic acid supplements
  • Fortified foods

What you might notice

  • No symptoms

Testing

Who should test
Anyone planning pregnancy, with anaemia, heavy alcohol use, or on medicines that affect folate.
How to prepare
Fasting is often recommended because a recent meal can raise the result.
When to retest
8–12 weeks after starting a supplement.

What can help

Food sources

Spinach and other greensDal, rajma and chanaCitrus fruitPeanutsFortified cereals

See a doctor if you're planning a pregnancy and your level is low, or if you have anaemia.

Common questions

Serum or RBC folate?

Serum shows the last few days; RBC folate shows the last few months.

Why take B12 with folate?

Folate alone can correct anaemia while a B12 deficiency keeps damaging nerves.

Explore further

Sources

  1. NIH Office of Dietary Supplements: Folate fact sheet for health professionals

Free nutrition assessment

Not sure what your body needs?

Answer a few questions about your diet, lifestyle and goals, and SYNC builds a personalised supplement plan with the reason for every suggestion. Free, about 6–8 minutes.

Build My Nutrition Plan

For general education only, not medical advice. Ranges shown are typical for adults; the range printed on your lab report applies. Talk to a qualified doctor about your results.