Methylfolate and B12: How They Work Together
Folate and vitamin B12 are two B vitamins that work as a team. Here’s how the partnership works, and how to get enough of both.
Key takeaways
- Methylfolate and B12 work together to process homocysteine.
- Adults need 2.4 mcg of vitamin B12 a day.
- High-dose folate can hide low B12, so doctors check both.
- Vegans, adults over 50 and people on some medicines are more likely to run low on B12.
A natural partnership
Methylfolate hands over a small “methyl group” to turn homocysteine into methionine. The enzyme that does this needs vitamin B12 to work. Methylfolate supplies the material, and B12 helps put it to use.
What vitamin B12 does
Vitamin B12 helps keep your blood and nerve cells healthy and helps make DNA. Adults need 2.4 mcg a day.
It’s found naturally only in animal foods such as fish, meat, eggs and dairy. Some breakfast cereals and nutritional yeasts are fortified with it.
Why doctors check both
Low folate and low B12 can both cause a type of anemia that leaves you tired and weak. Large amounts of folate can correct the anemia caused by low B12, but not the nerve damage, so a B12 problem can be missed. That’s why doctors usually check both.
The NIH sets an upper limit of 1,000 mcg a day for folate from supplements and fortified foods, unless your doctor advises more.
Who’s more likely to run low on B12?
- People who eat little or no animal foods
- Adults over 50, who may absorb less B12 from food
- People with pernicious anemia, atrophic gastritis, celiac or Crohn’s disease
- People who have had stomach or weight-loss surgery
- People taking metformin or acid reducers such as PPIs or H2 blockers
Your body stores a lot of B12, so it can take years for low levels to show.
Getting both every day
- Folate: leafy greens, beans, peas, citrus and enriched grains.
- B12: fish, eggs, dairy, meat, or fortified cereal and nutritional yeast.
- Easy combos: a spinach omelet, or salmon with broccoli.
A supplement that pairs methylfolate with B12 covers both in one step.
Already diagnosed?
If you’ve been diagnosed with B12 deficiency or pernicious anemia, follow your doctor’s treatment plan. It often involves B12 shots, and a supplement isn’t a replacement.
Frequently asked questions
Should I take folate and B12 together?
They work as a team, so many people choose a supplement with both. If your doctor has prescribed either one, follow their advice.
Which form of B12 is best?
You’ll see cyanocobalamin, methylcobalamin, adenosylcobalamin and hydroxocobalamin on labels. The NIH says research hasn’t shown that one form is better than the others.
Can you take too much B12?
The NIH says vitamin B12 hasn’t been shown to cause harm, even at high doses.