Folate vs B12
| Feature | Folate | Vitamin B12 |
|---|---|---|
| Role | DNA synthesis, cell division | DNA synthesis + nerve myelin + homocysteine |
| Anaemia type | Megaloblastic (high MCV) | Megaloblastic (high MCV) |
| Nerve damage | No | Yes — subacute combined degeneration |
| Stores | Weeks–months (depleted faster) | Years (large hepatic stores) |
| Pregnancy importance | Critical — neural tube defects | Also important |
| Main food sources | Green leafy veg, legumes, fortified foods | Animal products only |
Causes of Folate Deficiency
- Poor diet (low in green vegetables, legumes, fortified foods)
- Alcohol excess (interferes with absorption and increases demand)
- Coeliac disease and other malabsorption syndromes
- Pregnancy and lactation (high demand)
- Methotrexate and phenytoin (drug antagonists of folate)
- Haemodialysis (folate lost during dialysis)
- Haemolytic anaemia (increased red cell turnover)
Red Cell Folate is More ReliableSerum folate reflects recent dietary intake and can be transiently normal after a single meal. Red cell folate better reflects tissue stores over the preceding 2–3 months — request both.
When should I take folic acid in pregnancy?
Start folic acid (400 μg/day) at least 1 month before conception and continue until 12 weeks. Women with epilepsy, diabetes, obesity (BMI>30), or previous NTD-affected pregnancy should take 5 mg/day.
Can folate deficiency cause depression?
Low folate is associated with depression and poor antidepressant response. Augmenting antidepressants with folic acid (methylfolate) has evidence in some patients.
What is the difference between folate and folic acid?
Folic acid is the synthetic, oxidised form used in supplements and food fortification. Folate is the naturally occurring reduced form found in food. Both are converted to active 5-methyltetrahydrofolate in the body.
Does high folate mask B12 deficiency?
Yes — this is clinically important. High-dose folate supplementation can correct the anaemia of B12 deficiency but leave the neurological damage untreated. Always check both B12 and folate together.
Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.