Vitamin B6, also known as pyridoxine, is one of eight vitamins in the B complex group. Even though it was discovered in 1932, scientists are still learning new things about it.

Most people get enough B6 in their diet, but if you are deficient in other B complex vitamins, such as folate and B12, you’re more likely to be deficient in vitamin B6 as well (1Trusted Source).

Vitamin B6 deficiency is more common in people with liver, kidney, digestive or autoimmune diseases, as well as smokers, obese people, alcoholics and pregnant women (2Trusted Source, 3, 4Trusted Source).

In your body, B6 is involved in more than 150 enzyme reactions. These help your body process the protein, carbs and fat you eat. B6 is also closely linked with the functions of your nervous and immune systems (3, 5Trusted Source, 6Trusted Source).

More recently, it’s been found that B6 has antioxidant and anti-inflammatory properties. This means that it may play a role in helping prevent chronic conditions like heart disease and cancer (5Trusted Source, 7Trusted Source, 8Trusted Source).

Here are 9 signs and symptoms of vitamin B6 deficiency.

1. Skin Rashes

Vitamin B6 deficiency is one cause of a red, itchy rash called seborrheic dermatitis.

The rash can appear on your scalp, face, neck and upper chest. It’s known for its oily, flaky appearance and may cause swelling or white patches (9Trusted Source).

One reason B6 deficiency may result in skin rashes is that the vitamin helps synthesize collagen, which is needed for healthy skin. In these cases, consuming B6 may clear up the rash quickly (10Trusted Source, 11Trusted Source).

Some people affected with seborrheic dermatitis may have higher requirements for B6. A B6 face cream has helped some people improve symptoms from seborrheic dermatitis (12).

SUMMARY

An itchy, oily and flaky rash is a common sign of B6 deficiency. Consuming enough B6 generally helps clear up the rash quickly in cases of deficiency.

2. Cracked and Sore Lips

Cheilosis, which is characterized by sore, red and swollen lips with cracked mouth corners, can result from B6 deficiency. Cracked areas may bleed and become infected.

In addition to being very painful, having cracked and sore lips can make activities like eating and talking difficult.

Correcting B6 deficiency with foods rich in the vitamin or a supplement may clear up these symptoms.

Notably, deficiencies of riboflavin, folate, iron and other nutrients can also cause this condition, as can sunny, dry or windy weather and other external factors (13Trusted Source, 14Trusted Source).

SUMMARY

Sore lips with cracks in the corners of your mouth can be a sign of B6 deficiency. If that’s the case, getting enough B6 through food or a supplement could heal your lips.

3. Sore, Glossy Tongue

If you have a B6 deficiency, your tongue may become swollen, sore, smooth, inflamed or reddened. This is called glossitis.

The glossy, smooth surface of the tongue is due to the loss of papillae. Those are the bumps on your tongue. Glossitis can cause problems chewing, swallowing and talking.

Replenishing B6 treats glossitis, provided that a deficiency is the only cause.

Deficiencies of other nutrients, including folate and B12, can also result in this condition. Consuming enough of all these vitamins may then be needed to clear up glossitis (15).

SUMMARY

A swollen, inflamed, glossy-looking tongue is a sign of B6 deficiency. Shortfalls of other nutrients, particularly folate and B12, may also contribute to the condition.

4. Mood Changes

Shortfalls of B6 may affect your mood, sometimes contributing to depression, anxiety, irritability and increased feelings of pain (16Trusted Source).

That’s because B6 is involved in the making of several neurotransmitters, such as serotonin and gamma-aminobutyric acid (GABA). Both serotonin and GABA help control anxiety, depression and feelings of pain.

The role of B6 in combating such mood issues is being tested in a variety of conditions.

For example, in about half of individuals with autism, supplementing with B6 helps decrease behavioral problems, possibly because it helps produce neurotransmitters (17Trusted Source).

Research also suggests that taking 50–80 mg of B6 supplements daily may help with symptoms of premenstrual syndrome (PMS), such as moodiness, irritability, anxiety and depression (18Trusted Source, 19Trusted Source).

One possible reason B6 may help with PMS is because it helps make serotonin, which lifts your mood. Scientists are doing more research to figure out if women who experience PMS may actually have vitamin and mineral deficiencies (19Trusted Source, 20Trusted Source, 21Trusted Source).

SUMMARY

Mood changes like irritability, anxiety and depression can happen when you’re low in B6. That’s because B6 is needed to make nerve messengers that help control your mood.

5. Weakened Immune Function

A well-working immune system is key to preventing infections, inflammation and various cancers. Nutrient deficiencies, including B6, can disrupt the immune system.

More specifically, a deficiency in B6 can result in the decreased production of antibodies needed to fight infections (22Trusted Source).

A B6 deficiency may also reduce your body’s production of white blood cells, including T cells. These cells regulate immune function, helping it respond appropriately.

Additionally, B6 helps your body make a protein called interleukin-2, which helps direct the actions of white blood cells (23Trusted Source).

People with autoimmune disorders (in which the immune system turns against itself), can have increased destruction of B6, which increases the need for the vitamin (2Trusted Source).

SUMMARY

If you don’t get enough B6, your body can’t make the antibodies, white blood cells and other immune factors it needs to fight germs and ward off diseases.

6. Tiredness and Low Energy

A vitamin B6 deficiency can leave you feeling unusually tired and sluggish.

A big reason is vitamin B6’s role in helping make hemoglobin. That’s the protein in your red blood cells that helps carry oxygen throughout your body.

If your cells don’t get enough oxygen as a result of too little hemoglobin, it’s called anemia. That can make you feel tired and weak.

There have been select cases of B6-related anemia in which taking the inactive pyridoxine hydrochloride (HCl) form of the vitamin didn’t help. However, supplementing with the body’s most active form of B6, called pyridoxal 5’-phosphate (PLP), resolved the anemia (16Trusted Source).

You can buy either form of B6 as a supplement, but pyridoxine HCl is more common and generally costs less than PLP.

Besides feeling tired from anemia, B6 deficiency could also potentially contribute to tiredness due to its role in making the sleep-promoting hormone melatonin (24Trusted Source, 25Trusted Source).

SUMMARY

Vitamin B6 is needed to help make the red blood cells that transport oxygen throughout your body and help you feel energized.

7. Tingling and Pain in Hands and Feet

Deficiency of B6 can cause nerve damage called peripheral neuropathy.

Symptoms may include burning, shooting and tingling pain in your arms, legs, hands and feet. Some describe it as a “pins and needles” feeling.

The nerve damage may also result in clumsiness, balance problems and difficulty walking (26).

Additionally, continually taking too much of the inactive form of B6 (pyridoxine HCl) from supplements can also cause neuropathy. This may happen because large amounts of inactive B6 can compete with and block the active PLP form of B6 in your body (27Trusted Source).

Nerve problems from B6 deficiency are reversible with adequate B6 intake. On the other hand, nerve problems from B6 toxicity may be more difficult to treat.

SUMMARY

Burning, shooting pains in your limbs, hands and feet can be caused by nerve damage from B6 deficiency or overdose.

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8. Seizures

Seizures happen for different reasons, including B6 deficiency.

Without enough B6, you don’t make adequate amounts of the calming neurotransmitter GABA, so your brain may become overstimulated.

Seizures can cause symptoms such as muscle spasms, rolling eyes and jerky arms or legs. Sometimes people have rapid, uncontrollable shaking (convulsions) or lose consciousness.

A deficiency of B6 is well-known to cause seizures in newborns. The first cases were noted in the 1950s when babies were fed infant formula with insufficient B6 (26).

More recently, seizures due to B6 deficiency have been reported in adults. These cases were most commonly found in pregnancy, alcoholism, medication interactions or liver disease (6Trusted Source, 28Trusted Source).

Correcting B6 deficiency has proven very successful in treating related seizures.

SUMMARY

Seizures are an uncommon but possible result of B6 deficiency. This is more frequently seen in infants but has happened in adults as well.

9. High Homocysteine

Homocysteine is a byproduct created during protein digestion.

A B6 deficiency, as well as folate and B12, can result in an abnormally high blood level of homocysteine, as these B vitamins are needed to help process homocysteine (29Trusted Source).

Increased homocysteine levels have been linked with several health issues, most notably heart disease and stroke, as well as Alzheimer’s disease. When homocysteine is elevated, it can damage blood vessels and nerves (30Trusted Source, 31Trusted Source, 32Trusted Source, 33Trusted Source).

Fortunately, your homocysteine level can be checked with a simple blood test. Generally, elevated homocysteine can be lowered by taking B6, B12 and folate supplements.

Just keep in mind that other factors, such as your eating habits and physical activity, are also typically involved in diseases linked with high homocysteine and must be addressed.

SUMMARY

A deficiency of B6, as well as folate and B12, may cause a high homocysteine level, which can damage blood vessels and nerves and increase the risk of disease.