Folate deficiency hits more people than you expect — but it’s easy to miss early on.

Low folate can cause fatigue, mouth sores, diarrhea, and trouble concentrating. Pregnant people, older adults, and anyone with poor diet or certain medical conditions are more likely to run low. This page gives clear, practical steps to spot folate deficiency, confirm it with tests, and fix it fast so you don’t end up with preventable complications.

What causes folate deficiency?

Poor diet is the top reason. Folate (vitamin B9) is found in leafy greens, beans, citrus, and fortified grains. If you rarely eat these foods, your stores can drop in a few months. Alcohol misuse, some gut problems (like celiac or Crohn’s), and chronic use of certain meds — methotrexate, some anticonvulsants, and sulfasalazine — can also block folate absorption. Pregnancy increases needs, so prenatal folate is crucial.

How do you know if you’re deficient? Key signs are persistent tiredness, pale skin from anemia, shortness of breath during activity, and tingling or numbness in hands and feet. Some people notice forgetfulness or mood changes. Your doctor will check a complete blood count (CBC) and measure serum folate and red blood cell folate. Low hemoglobin with large red blood cells (macrocytic anemia) often points to folate or B12 deficiency, so they may test both.

Treatment is straightforward.

For most adults, doctors recommend oral folic acid 400 to 1000 micrograms daily until levels normalize. Pregnant people often need 600 to 800 micrograms daily to prevent neural tube defects. If malabsorption is the issue, higher doses or injections might be required. Always follow medical advice — high folic acid can mask B12 deficiency, which needs separate treatment.

Diet fixes that work. Add spinach, kale, lentils, chickpeas, asparagus, and oranges to meals. Choose fortified cereals or whole-grain bread if you struggle with fresh produce. A simple salad a day plus a serving of beans or lentils a few times weekly covers most needs. For pregnant people, take a prenatal vitamin with folic acid as directed.

When to see a doctor. If you have lasting fatigue, shortness of breath, unexplained weakness, or if you’re pregnant and not taking prenatal vitamins, get tested. Also check if you take medications that interfere with folate or have digestive disease.

Preventing relapse means steady intake. Track folate-rich foods, limit alcohol, and review medications with your clinician. If you have repeated low levels despite diet changes, ask about testing for absorption problems or genetic issues that affect folate metabolism.

If you’re on meds like methotrexate, your doctor may pair folic acid with your treatment, reducing side effects. Lab checks repeat after 4 to 8 weeks of treatment. Keep a simple food log and bring it to appointments — it helps your clinician tweak doses fast easily.

Want quick tips? Start a weekly meal plan: two leafy-green meals, three legume servings, and fortified cereal for breakfast. Keep a multivitamin on hand if your diet is spotty. With simple steps, folate deficiency is one of the easiest nutrition problems to solve.