Vitamin B6: Benefits, Sources & Deficiency Symptoms

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Vitamin B6 is also called pyridoxine, and it’s a water-soluble vitamin that can only be derived from foods such as pork, fish, and poultry.

It supports the immune system, the nervous system, the brain, and other bodily functions.

This article will explore Vitamin B6 in detail, looking at its benefits, usage, side effects, safety, and biological functioning.

If you’re interested in learning more about this substance, we’re here to provide you with the facts.

This information should help you decide if supplementing with this vitamin would be good for your body and beneficial to your health.

Overview: B Vitamins

There are eight B vitamins in existence, and most of them are required to help the body’s enzymes carry out different functions.

They perform tasks like taking nutrients that contain energy and oxygen all over the body, metabolizing carbohydrates, helping with cellular function, repair DNA/RNA, supporting brain health, and others (1, 2).

The B Vitamins are antioxidants that play a role in boosting immune functioning.

In addition, there’s some evidence they have anti-inflammatory properties which could help with conditions where there’s swelling involved (3).

Vitamin B6, in particular, is known for the key role it plays in health and disease. However, it’s rarely taken as a separate supplement, but as part of an overall multivitamin.

What is Vitamin B6?

Vitamin B6 is one of the B-complex vitamins, and it helps to support over 100 enzymes in the body.

We get this substance solely from food, as the body doesn’t store it.

The key functions of this vitamin are to help metabolize fats and carbohydrates, support the immune system, nervous system, and the liver, skin, hair, and eyes, and produce key neurotransmitters related to brain development and mood. (4).

Sources of Vitamin B6 include a number of different foods. Some of these are bread, eggs, chicken, pork, vegetables, milk, soya beans, peanuts, lentils, beans, bananas, potatoes, fish, wholegrain cereals, and some fortified breakfast cereals (4, 5).

How Does It Work?

One of the key roles of Vitamin B6, along with other B vitamins, is to assist in converting carbohydrates into glucose, which is then used by the body as energy. In addition, this substance is involved in the metabolism of fats and protein (4).

Vitamin B6 is heavily involved in the development of certain key neurotransmitters that are involved in the proper functioning of the brain.

It helps make the important mood neurotransmitters serotonin and norepinephrine, as well as melatonin which helps regulate our circadian rhythm (4).

This crucial vitamin also regulates the amount of an amino acid called homocysteine in the blood. Levels of this substance in the body are thought to be related to the development of heart disease (4).

Finally, B6 is required in order to help with the absorption of Vitamin B12, which produces red blood cells and other cells that support immune functioning (4).

Is It Safe?

There can be some unpleasant side effects associated with too much of this substance. The Vitamin B6 you get from foods is very unlikely to get you to dangerous levels (1).

However, heavy supplementation over a long period of time could cause symptoms like nausea, loss of control of body movements, and neuropathy in the hands and feet. This may occur if you take from 200-1000 mg per day (1).

Other side effects may include headache, nausea, stomach pain, sensitivity to sunlight, and loss of appetite (4).

Vitamin B6 Health Benefits

Vitamin B6 Health Benefits

1. Stroke and Heart Disease

Vitamin B6 works together with folate and Vitamin B12 to lower levels of homocysteine in the body.

High levels are associated with blood clots, damaged blood vessel function, and higher incidence of heart attack and stroke (1).

Despite this, the research has been somewhat mixed in terms of the connection between Vitamin B6 intake and reduced risk of heart disease. However, some studies do support this connection.

What the Science Says

A Japanese study published in Stroke found that supplementation with Vitamin B6 led to a reduced risk of death from stroke, coronary heart disease, and heart failure in men and women.

A research study in Nutrients looked at the Korean population and levels of B6. They concluded that intake of this vitamin was linked to a lowered risk of getting cardiovascular disease.

Research published in JAMA looked specifically at women’s levels of Vitamin B6 in relation to heart disease.  They found that supplementation of B6 was important in the prevention of coronary heart disease in women.

2. Promote Brain Health

Vitamin B6 plays a key role in brain health. It helps in the production of key brain neurotransmitters which are important for the development of this organ.

It also assists in producing serotonin and norepinephrine, which are neurotransmitters involved in mood (4).

In addition, there’s some evidence that Vitamin B6 is related to cognitive decline in elderly people.

Higher levels of this vitamin in the body have been associated with better mental functioning, although the results in the research are quite mixed.

What the Science Says

A review of the research published in the Archives of Internal Medicine looked at studies about the effect of Vitamin B6 levels on people with normal cognitive function, dementia, or ischemic vascular disease.

They did not find enough evidence to prove a link between this vitamin and cognitive function.

A study published in the American Journal of Clinical Nutrition looked at 70 male participants aged 54-81 years. They found a correlation between higher Vitamin B6 levels and performance on memory tests.

3. Morning Sickness

During pregnancy, many women experience vomiting and nausea. Although termed ‘morning sickness’, these symptoms may occur throughout the day. There’s some evidence that taking Vitamin B6 may be an effective treatment.

Vitamin B6 is recommended by the American College of Obstetricians and Gynecologists as a treatment for morning sickness (1).

What the Science Says

A study of 59 women published in Obstetrics and Gynecology gave women 25mg of B6 every 8 hours for 72 hours. They found that supplementing with Vitamin B6 reduced severe nausea in pregnant women.

Another research project published in the Journal of Maternal, Fetal, and Neonatal Medicine looked at 77 women with morning sickness.

They discovered that a dosage of 40mg of Vitamin B6 twice a day lessened the symptoms of mild to moderate morning sickness.

4. Premenstrual Syndrome

Premenstrual syndrome is a series of symptoms that sometimes occur in the days before a woman menstruates.

These may involve mood swings, fatigue, depression, tender breasts, and irritability (6).

There is some evidence that Vitamin B can have a positive effect on lessening these symptoms.

However, the quality of the research has been quite low, so clearly, further research needs to be done exploring this connection.

What the Science Says

A systematic review of the research in the BMJ concluded that dosages of 100mg/day of Vitamin B6 can effectively treat the symptoms of PMS and premenstrual depression.

The researchers acknowledge that the results may be questionable because of the quality of the studies.

5. Depression

One cause of depression is lowered levels of key neurotransmitters in the brain, particularly serotonin and also norepinephrine.

Vitamin B6 may be an effective remedy for depressed mood because it produces these chemicals, raising levels in the neocortex.

When these levels go up, mood should improve. There’s some research linking low levels of Vitamin B6 with depressed mood, although other studies show a limited connection.

What the Science Says

A systematic review of the research in Family Practice looked at studies of Vitamin B6 as a treatment for depression in perimenopausal women. The results indicated that this was not a meaningful or helpful treatment for depression in this population.

However, because these studies only looked at one group only, it was suggested that further research be carried out with other groups.

Another study in Psychotherapy and Psychosomatics looked at 140 participants with major depression and found that there was a link between depression and low levels of Vitamin B6.

On the whole, more studies need to be conducted to confirm this link and to explore whether this vitamin is a suitable treatment for depression.

6. Cancer

There’s some evidence that low levels of Vitamin B6 are related to the risk of developing cancer.

There is also research showing that taking Vitamin B6 will actually prevent cancer or lessen the side effects of chemotherapy, but it’s somewhat limited (7).

What the Science Says

A study published in the American Journal of Clinical Nutrition showed that patients with advanced breast cancer had much lower levels of Vitamin B6 than healthy participants.

In addition, a review of 121 studies in the Journal of the National Cancer Institute concluded that evidence supports the potential of Vitamin B6 as a cancer risk reduction agent.

Vitamin B6 Deficiency and Side Effects

Vitamin B6 Sources

A deficiency in this key vitamin has to be severe to lead to serious side effects. With a slight lack of B6, there likely won’t be any consequences (1).

However, a long-term or significant decrease could lead to symptoms such as depression, confusion, skin conditions, microcytic anemia, and decreased immune functioning (1).

Recommended Daily Allowance

The recommended dosages of Vitamin B6 vary based on age and gender. They are as follows (1):

  • Men from 14-50 years – 1.3 mg/day
  • Men over 51 years -1.7 mg
  • Women 14-18 years – 1.2 mg
  • Women 19-50 years – 1.3 mg
  • Women 51 + years – 1.5 mg
  • Pregnant women – 1.9 mg
  • Breastfeeding women – 2.0 mg

Drug Interactions

There are a number of medications that can interact with Vitamin B6. Here are some of the key interactions (4, 8):

  • Antibiotic Tetracycline – B Vitamins including B6 create difficulty absorbing this antibiotic. You can take them both, just take them at different times of the day.
  • Monoamine Oxidase Inhibitors – These antidepressant medications can lower levels of B6 in your system.
  • Chemotherapy Drugs -Vitamin B6 may diminish the side effects of some of the chemotherapy medications.
  • L-Dopa – Vitamin B6 can lower the effectiveness of this medication, which is for the treatment of Parkinson’s Disease.
  • Phenytoin (Dilantin) – This seizure medication is rendered less potent when taken alongside Vitamin B6.
  • Erythropoietin (EPO) – This is a drug used to treat anemia. It could have the effect of diminishing the amount of Vitamin B6 in your system.
  • Amiodarone (Cordarone) – This heart medication can make your skin more reactive to the sun. If you take it with Vitamin B6, it exacerbates this effect.
  • Barbiturates – These nervous system medications could be less effective when combined with Vitamin B6.


What Causes Vitamin B6 Deficiency?

There are a number of medical conditions that can cause Vitamin B6 deficiency, including renal and kidney disorders, auto-immune conditions, alcoholism, genetic conditions like homocystinuria, celiac disease, Crohn’s disease, and ulcerative colitis.

Antiepileptic medications can also lead to a deficiency (7).

Can I Take Vitamin B6 and Vitamin B12 together?

Yes, you can, and you should, as many vitamins work together. A multivitamin should include several of the B vitamins, including 6 and 12.

Does Vitamin B6 Help You Sleep?

Yes, it does. Vitamin B6 helps in the production of a hormone called melatonin, which is key in regulating our internal body clock and sleep-wake cycle.

When levels of melatonin rise, this causes us to become sleepy.

What Time of Day Should I Take Vitamin B6?

You should take any of the B vitamins in the morning, for best absorption.

At night your digestion slows down, which could lead the supplement to absorb poorly into your system (9).

Can Vitamin B6 Help With Weight Loss?

Many people believe that Vitamin B6 can help with weight loss because it’s involved in the metabolizing of fats and carbohydrates.

However, there’s very little evidence to support this supposition (10).

The Bottom Line

Vitamin B6 is an essential vitamin that plays several key functions in the body. It helps to regulate metabolism, produce key brain chemicals, and support immunity.

It also particulates in the functioning of the nervous system, liver, skin, hair, and eyes.

Vitamin B6 is associated with the treatment of a number of conditions, including stroke, depression, seizures, morning sickness, PMS, and sideroblastic anemia. In addition, it supports brain health.

Vitamin B6 is usually not given as a separate supplement but as part of a multivitamin or B Vitamin complex.

As there are some possible side effects at very high amounts, so check your dosages carefully and confirm your usage with your doctor.

At the right doses, this is a helpful supplement that can provide you with numerous benefits.


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