Folate is a B vitamin your body uses to build and repair DNA, and to make new cells

Folate (also called vitamin B9) is a nutrient that helps your cells divide and grow. Every time your body makes a new cell — whether that's a red blood cell, a skin cell, or a nerve cell — folate plays a role in copying the genetic instructions that go into it. Without enough folate, your cells can't divide properly, which affects everything from your energy level to how your immune system works.

Your body cannot make folate on its own, so you have to get it from food or supplements. Some foods naturally contain folate (leafy greens, legumes, asparagus), while others are fortified with a synthetic version called folic acid (many breads, cereals, and grain products). Both forms work in your body, though some people process one form more efficiently than the other.

Key Takeaways

  • Folate helps your body make new cells and copy DNA, which is why it matters for growth, healing, and everyday cell turnover.
  • Folate works closely with vitamin B12 to manage a compound called homocysteine; when both are low, homocysteine can build up and affect heart and brain health.
  • Pregnant people need more folate because the vitamin is critical for fetal brain and spine development in the earliest weeks of pregnancy.
  • Folate deficiency can cause fatigue, weakness, and a type of anemia where red blood cells are larger than normal.
  • You get folate from leafy greens, beans, lentils, asparagus, and fortified grains, or you can take it as a supplement.

How folate supports energy and red blood cells

One of the most noticeable effects of low folate is fatigue. This happens because folate is essential for making red blood cells, which carry oxygen throughout your body. When you don't have enough folate, your body produces fewer red blood cells, and the ones it does make are often larger and less effective than normal. This condition is called megaloblastic anemia, and it leaves you feeling tired and weak even when you've had enough sleep.

The fatigue from folate deficiency can be gradual — you might not notice it happening. You may feel less energetic during exercise, struggle to concentrate, or find that everyday tasks feel harder. Once you restore your folate levels, many people report that their energy returns within a few weeks, though it can take longer for red blood cell counts to fully normalize.

Folate and heart health through homocysteine management

Folate works alongside vitamin B12 and vitamin B6 to break down a compound called homocysteine. Homocysteine is a normal byproduct of protein metabolism, but when it builds up in your blood, it may contribute to damage in blood vessels and affect heart health. Folate helps keep homocysteine at lower levels by converting it into other compounds your body can use or excrete.

This is why folate deficiency is sometimes linked to cardiovascular concerns — not because folate directly prevents heart disease, but because low folate allows homocysteine to accumulate. If you have a family history of heart disease or have been told your homocysteine is elevated, your doctor may recommend checking your folate and B12 levels as part of a broader assessment.

Folate's critical role in pregnancy and fetal development

Folate is especially important during pregnancy because the developing fetus needs it to form its brain, spinal cord, and other neural structures. The neural tube — which becomes the brain and spine — develops in the first 28 days of pregnancy, often before a person knows they are pregnant. Adequate folate during this window significantly reduces the risk of neural tube defects like spina bifida and anencephaly.

For this reason, people who are pregnant or planning to become pregnant are advised to get more folate than the general population. Many prenatal vitamins contain folic acid (the synthetic form of folate) at higher doses than a standard multivitamin. Even if you are not currently pregnant, maintaining adequate folate is important because pregnancy-related needs begin before a positive test.

Signs that your folate level might be low

Folate deficiency develops gradually, and early signs can be subtle. Common symptoms include persistent fatigue, weakness, shortness of breath, difficulty concentrating, and mood changes like irritability or depression. Some people experience tingling or numbness in their hands and feet, though this is more common when B12 is also low.

Folate deficiency can also show up as mouth sores, a swollen tongue, or digestive problems like diarrhea. If you notice any of these symptoms, especially if they persist for more than a few weeks, it's worth mentioning to your doctor. A straightforward blood test can measure your folate level and help determine whether low folate is contributing to how you feel.

Food sources of folate and how much you need

The recommended daily amount of folate for most adults is 400 micrograms (mcg). Pregnant people need 600 mcg, and those breastfeeding need 500 mcg. These amounts are higher because folate is being used not just for your own cells but also for fetal or infant development.

Folate is abundant in leafy greens like spinach, kale, and romaine lettuce; legumes like lentils, chickpeas, and black beans; and vegetables like asparagus, broccoli, and Brussels sprouts. Fortified grains — bread, pasta, rice, and cereals — also contain significant folate. A single serving of cooked spinach or a cup of lentil soup can provide a substantial portion of your daily need. If you eat a varied diet with vegetables and whole grains, you can usually meet your folate needs through food alone.

When and why people take folate supplements

Some people take folate supplements because they don't eat enough folate-rich foods, have a condition that affects nutrient absorption, or are pregnant. Others take it because their doctor found low folate on a blood test. Folate supplements come in two main forms: folic acid (the synthetic version) and methylfolate (a form closer to what your body naturally uses). Most over-the-counter supplements and fortified foods use folic acid, which is effective for most people.

If you have a genetic variation that affects how you process folic acid — something your doctor can test for — methylfolate may work better for you. Folate supplements are generally considered safe at recommended doses, though very high doses over long periods are not recommended. If you're considering a supplement, it's worth discussing with your doctor, especially if you're taking other medications or have a health condition that affects nutrient absorption.

Folate and mental health

Emerging research suggests that folate may play a role in mood and mental health. Folate is involved in making neurotransmitters — the chemical messengers in your brain that regulate mood, motivation, and stress response. Some studies have found that people with depression or anxiety have lower folate levels than those without these conditions, though researchers are still working to understand whether low folate contributes to mood problems or whether mood problems lead to poor nutrition.

What is clear is that folate deficiency can worsen fatigue and concentration, which can make depression or anxiety feel more severe. If you're managing a mood condition and have noticed persistent fatigue or brain fog, asking your doctor to check your folate level is a reasonable step. Restoring adequate folate won't replace other treatments, but it may be one piece of supporting your overall mental health.

Frequently Asked Questions

What's the difference between folate and folic acid?

Folate is the natural form of vitamin B9 found in food. Folic acid is the synthetic version used in supplements and fortified foods. Both work in your body, but some people process folic acid less efficiently due to genetics. If you've been told you have a MTHFR variation, methylfolate (a different synthetic form) may work better for you than standard folic acid.

Can you get too much folate?

Folate from food is not toxic at high levels because your body excretes excess amounts. Very high doses of folic acid supplements over long periods are not recommended, though occasional high doses are generally considered safe. If you're taking a supplement, stick to the recommended dose on the label unless your doctor advises otherwise.

Does cooking destroy folate in vegetables?

Folate is sensitive to heat and can be reduced by cooking, especially boiling. Steaming, microwaving, or eating vegetables raw preserves more folate than long cooking times. If you're concerned about folate intake, eating some vegetables raw or lightly cooked is a good strategy, though cooked vegetables still contain meaningful amounts.

Can low folate cause weight gain?

Low folate itself doesn't directly cause weight gain, but the fatigue and reduced energy it causes can make it harder to stay active. Additionally, folate deficiency can affect metabolism and mood, which may indirectly influence eating patterns. If you've gained weight and feel unusually tired, checking your folate level is worth doing as part of a broader health picture.

Is folate the same as folic acid in prenatal vitamins?

Most prenatal vitamins contain folic acid rather than natural folate, and this is considered safe and effective for pregnancy. However, some prenatal vitamins now offer methylfolate as an option. Either form will support fetal development, though if you know you have a MTHFR variation, discussing which form is best for you with your doctor is helpful.