Vitamin B, which is also known as pyridoxine, is a type of water-soluble vitamin that can be found in different food sources. Vitamin B6 is an essential nutrient, which means that your body needs it to grow and sustain different biological processes, but you can’t produce it on your own. As a result, you need to make sure that you’re consuming enough of this nutrient to avoid a B6 vitamin deficiency.

Keep reading to learn more about the causes, symptoms and risks of vitamin B6 deficiency.

Vitamin B6 functions

The most common form of vitamin B6 found in the human body is called pyridoxal 5’ phosphate (PLP). According to the Harvard T.H. Chan School of Public Health, PLP acts as a coenzyme that assists other enzymes so they can perform different roles inside your body. PLP is involved in more than 140 enzymatic processes in the human body.

According to MedlinePlus, some of the functions of vitamin B6 include:

Assisting in the breakdown of proteins and fats
Helping your body regulate blood sugar levels
Maintaining healthy levels of an amino acid called homocysteine
Supporting your brain health and immune function
Participating in hemoglobin production
Aiding in cognitive development
Sustaining normal nerve function

B6 deficiency causes

B6 deficiency is uncommon in the United States and other developed countries, as long as you’re eating a balanced diet. In very rare cases, consuming a diet high in processed foods can lead to vitamin B6 deficiency, but this is rare. According to the MSD Manuals, other causes of low vitamin B6 levels can include:

Malabsorption disorders
Alcohol use disorder
Certain medications
Hemodyalisis
Kidney disease
Autoimmune disease
Thyroid disease
Congenital metabolism errors

B6 deficiency signs and symptoms

Symptoms of B6 deficiency in adults may be mild or unnoticeable, especially in cases of mild deficiency. However, chronic pyridoxine deficiency symptoms can include:

Sensory alterations
An itchy rash with flaky scales, called seborrheic dermatitis
Confusion
Altered mental status
Swollen tongue, or glossitis
Inflammation of the lips, or cheilitis
Seizures

Signs of vitamin B6 deficiency in infants can include seizures and anemia.

Vitamin B6 deficiency health risks

Vitamin B6 deficiency diseases have been studied extensively. For example, research has found that having healthy B6 levels may be associated with a lower risk of certain types of cancer.

Patients with seizures — especially children — who don’t respond well to antiseizure medications should be tested for B6 deficiency. People with other vitamin B deficiencies should also be tested. Measuring your serum pyridoxal phosphate levels is the most common way to test B6 levels, and at-home tests can also be helpful to monitor your condition.

Vitamin B6 is also linked to female reproductive health. This vitamin has been used to help treat morning sickness and nausea during pregnancy — however, it should only be taken under medical supervision if you’re pregnant. Some studies have also found that B6 may help relieve premenstrual syndrome (PMS) symptoms.

B6 food sources

There are many dietary sources of vitamin B6, both animal and plant-based. Fortunately, this means that you can get enough vitamin B6 from eating a balanced, mixed diet. According to the National Institutes of Health, foods that contain high amounts of vitamin B6 include:

Fish
Beef liver
Poultry
Organ meats
Potatoes
Starchy vegetables
Non-citrus fruit
Fortified cereals
Chickpeas

How much vitamin B6 do I need per day

The recommended dietary allowance (RDA) of vitamin B6 for teenage and adult males is 1.3 mg per day, and 1.7 mg for senior males. Teenage and adult females, on the other hand, need approximately 1.3 mg, and senior females require 1.5 mg of vitamin B6 per day.

Pregnant and breastfeeding women need around 1.9 mg mcg-2.0 mg of this vitamin everyday.

If you’re showing low vitamin B6 symptoms, your doctor may recommend taking a supplement. Vitamin B6 is available as a stand-alone supplement, and it’s also included in many multivitamins. The most common form of vitamin B6 included in supplements is pyridoxine, although PLP supplements are also available.

B6 vitamin toxicity & overdose

Since vitamin B6 is a water-soluble vitamin, your body is typically able to eliminate excess vitamin from your diet through urine. Vitamin B6 toxicity from food sources alone hasn’t been reported.

However, you can develop vitamin B6 toxicity from excessive supplementation. Taking 1-6 grams of pyridoxine per day for extended periods of time can lead to uncomfortable, and sometimes dangerous symptoms. But you would be unlikely to develop symptoms when taking a correct dosage of a B6 supplement.

According to the Mayo Clinic, some of the signs of vitamin B6 toxicity can include:

Loss of muscle control
Lack of movement coordination
Nausea
Heartburn
Disfiguring skin lesions
Increased sensitivity to light
Reduced skin sensitivity to pain and temperature
Numbness

If you have taken large doses of vitamin B6 and experience any of these symptoms, it’s important to seek medical attention.

Does vitamin B6 make you sleepy

Vitamin B6 is involved in the production of melatonin and serotonin, which are two hormones that play a role in restful sleep. Healthy levels of B6 may help you sleep better and improve your mood.