Signs of folate deficiency – symptoms and folate-rich foods

Signs of folate deficiency can be difficult to spot. You may feel unusually tired, become short of breath more quickly than before, or notice that your tongue is burning for no apparent reason. This is why low folate levels are sometimes missed, even though folate is needed every day for the body to form new cells and red blood cells. Folate is found naturally in our food, especially in green leafy vegetables and legumes, but many people still get too little of it.

Signs of folate deficiency – fill up on green leafy vegetables and legumes

What is folate deficiency and why does it affect the whole body?

Folate, sometimes called vitamin B9, is required for DNA synthesis and cell division. It is especially important in tissues with a high cell turnover, such as the bone marrow, where red blood cells are produced. In folate deficiency, these processes become impaired, which can lead to megaloblastic anemia—a condition in which red blood cells are abnormally large and immature.

For this reason, the symptoms are not simply related to a general “vitamin deficiency.” When the blood’s ability to transport oxygen is reduced, you may experience fatigue, palpitations, or shortness of breath during activities that were previously easy. In some cases, the first signs are more diffuse symptoms affecting the mouth or digestive system.

Folate and folic acid are not exactly the same. Folate is the naturally occurring form found in foods, whereas folic acid is the synthetic form used in dietary supplements and fortified products. The body can utilize both forms, but it is useful to understand the distinction because dietary recommendations and laboratory test results often refer to both terms.

Common signs of folate deficiency

The most common symptoms often develop gradually. Many people describe that they “don’t really recover”, despite sleep and rest. If the anemia becomes more obvious, the symptoms usually become easier to recognize.

Common signs of folate deficiency are:

• fatigue, weakness and decreased energy

• shortness of breath or rapid breathing

• palpitations

• headache

• pallor

• decreased appetite

• diarrhea or upset stomach

• sore, red or burning tongue, sometimes with mouth ulcers

A practical question many people ask is whether folate deficiency can feel like iron deficiency. The answer is yes – at least partially. Fatigue, pallor and dizziness can occur in both conditions. The difference is often first seen in blood tests, where the doctor assesses blood counts, the size of the red blood cells and levels of folate, B12 and iron.

It is also common to wonder if tingling means folate deficiency. Tingling, numbness and balance problems are more indicative of a vitamin B12 deficiency than of isolated folate deficiency. This is an important difference, since folic acid supplements can improve blood counts but at the same time hide a B12 deficiency that continues to damage the nervous system. Therefore, B12 deficiency should be ruled out before treating suspected folate deficiency with supplements.

Why does folate deficiency occur?

The most common cause of folate deficiency is inadequate dietary intake over an extended period. Although folate is found in a wide variety of foods, the amounts are often relatively small. A diet low in vegetables, legumes, fruit, and whole grains can therefore increase the risk of deficiency. According to the Swedish Food Agency, dark green leafy vegetables, cabbage, beans, chickpeas, lentils, fruit, and berries are particularly rich sources of folate.

Folate deficiency can also occur despite a generally balanced diet. Conditions that impair nutrient absorption, such as celiac disease and other malabsorptive disorders, may reduce folate levels. Excessive alcohol consumption, certain medications, and situations associated with increased folate requirements can also contribute. Pregnancy is a common example, as rapid cell growth and division significantly increase the body's need for folate.

Certain situations warrant particular attention:

• a one-sided diet or low intake of vegetables and legumes

• gastrointestinal diseases with reduced nutrient absorption

• high alcohol consumption

• pregnancy or planned pregnancy

• drugs that affect folate metabolism, such as methotrexate in certain doses and contexts

Fill up on green leafy vegetables and legumes

When folate intake needs to be improved, dietary changes are a natural place to start. Green leafy vegetables and legumes are particularly good sources, providing high amounts of folate relative to their calorie content. Examples include spinach, kale, arugula, broccoli, beans, chickpeas, and lentils. Fruit, berries, cabbage, whole-grain products, milk, and yogurt can also contribute to overall folate intake.

Increasing folate intake does not have to be complicated. A bowl of lentil soup for lunch, chickpeas added to a salad, or a handful of spinach in an omelette can make a meaningful difference over time. People following a vegetarian or plant-based diet often consume adequate amounts of folate, but should also pay attention to their vitamin B12 intake, as this nutrient is found primarily in animal-based foods.

Three simple ways to increase folate intake through food include:

• add beans, chickpeas or lentils to at least one meal a day

• choose dark green leafy vegetables several times a week

• replace parts of white bread or pasta with whole grain products

However, if a deficiency is detected, diet is not always sufficient as the only measure, especially if the levels are clearly low or if absorption is affected. In this case, doctors may recommend folic acid supplements for a period of time. The cause of the deficiency also needs to be assessed, otherwise there is a risk that the problem will recur.

When should folate levels be checked?

You should consider testing if you experience persistent fatigue, recurrent shortness of breath, paleness, or a sore, red tongue without an obvious cause. The same applies if you have gastrointestinal symptoms, follow a highly restrictive diet, or belong to a group at increased risk of folate deficiency. Blood tests can often provide valuable information, particularly when folate levels are assessed alongside a complete blood count and vitamin B12 levels.

When folate deficiency is suspected, testing typically includes a complete blood count as well as measurements of folate and vitamin B12. Homocysteine may sometimes provide additional information, as elevated levels can occur in individuals with folate or vitamin B12 deficiency. To ensure an accurate assessment, test results should always be interpreted in the context of symptoms, medical history, and other laboratory findings.

Pregnancy is a special case. Women who are trying to conceive are advised to take 400 micrograms of folic acid daily, starting before conception and continuing through the first 12 weeks of pregnancy. This helps reduce the risk of neural tube defects, including spina bifida, in the developing fetus. Folate requirements are also higher during pregnancy than in non-pregnant adults.

There may also be value in testing before symptoms become pronounced. People who exercise regularly, work under significant stress, or are planning a pregnancy may wish to determine whether low energy levels or reduced performance have an identifiable cause. In some cases, health screening can provide answers sooner than waiting for symptoms to progress.

Low folate levels do not simply reflect the status of a single vitamin. They can provide insight into how diet, gastrointestinal health, medications, and life circumstances may be affecting overall health. Identifying a deficiency early can make it easier to address the underlying cause and take appropriate action before symptoms become more significant.