Folate (B9) deficiency
Linked to Vitamin B9 (Folate)
Low folate impairs cell production, causing anaemia and — in pregnancy — birth defects.
Where it shows on the body
Rotate the figure and click a red marker to see the affected area. Internal organs open a 3D organ model.
Causes
- Low intake of greens and legumes
- Pregnancy
- Alcohol
- Some medications
- Malabsorption
Symptoms
- Fatigue and weakness
- Mouth sores
- Shortness of breath
- Irritability
- Pale skin
What happens if untreated
- Megaloblastic anaemia
- Neural tube defects in a developing baby
Who is most at risk
- People who could become pregnant
- Heavy drinkers
- Those with gut disorders
Prevention & sources
- Leafy greens, legumes, fortified grains
- 400 µg folic acid before and in early pregnancy
Correcting it: foods, amounts & timing
Foods that help & safe amounts
- Leafy greens, legumes and citrus daily
- Fortified grains
- 400 µg folic acid daily if you could become pregnant
Anaemia symptoms ease over a few weeks as new red cells form.
Sources & references
Symptoms overlap — testing matters
Most deficiency symptoms (fatigue, poor concentration, skin and hair changes) are shared across several nutrients and many unrelated conditions. A symptom on this page is a reason to investigate, not a diagnosis.
A GP can confirm or rule out a deficiency with a blood test and check for underlying causes such as absorption problems. Do not start high-dose supplements on suspicion alone — some nutrients are harmful in excess, and supplementing before testing can mask the underlying result.