Vitamin B6: Benefits and Nutrition Profile (2024)

Vitamin B6 (pyridoxine) is a water-soluble compound that is involved in over 100 enzyme reactions in the body.

It is crucial for the following:

• Brain development
• The formation of the energy source glucose
• Immune system function

Vitamin B6 is found in the following foods:

• Fish
• Beans
• Fruits
• Vegetables

Vitamin B6 can also be taken as a dietary supplement.

This article discusses the potential uses of B6, the risks of having too much or too little of it in your body, and how to optimize wellness by incorporating it into your diet.

Uses of Vitamin B6

The role of vitamin B6 has been studied extensively for cancer, dementia, and heart health. However, a lot of the evidence is mixed.

It's also been researched for people with depression, anxiety, nausea and vomiting, and more.

Here's a look at the science behind some of vitamin B6's potential uses.

May Increase Cognitive Function

Vitamin B6 has been thought to help maintain mental function and prevent cognitive decline, but there's little compelling evidence that it works.

The theory is that vitamin B6, along with other B-complex vitamins like B12 and folic acid, could help prevent memory loss or dementia by lowering hom*ocysteine in the body. High levels of hom*ocysteine are associated with cognitive impairment. Often these B vitamins have been studied in tandem, so the true effects of vitamin B6 are hard to determine.

Supplementation with B-complex vitamins decreases hom*ocysteine levels in people with Alzheimer's disease or dementia. But interestingly, a corresponding improvement in mental function hasn't been shown. And vitamin B supplementation was shown to have little or no effect on healthy older adults in terms of protecting against cognitive decline.

A review of 21 studies showed that high levels of B6 alone didn't impact the dementia risk of older adults, either.

May Protect Against Cancer

A review of 130 studies suggests that vitamin B6 may protect against cancer.

A higher intake of dietary vitamin B6 (from food sources) was associated with a significantly lower risk of cancer.

High dietary B6 levels were mainly associated with lower risks of cancers of the digestive tract, like esophageal, pancreatic, and colon cancers.

But interestingly, a high total intake of vitamin B6 (from foods plus supplements) had much less of an effect on cancer risk.

This could be because diets high in vitamin B6 are also loaded with other protective nutrients that decrease the odds of cancer.

And only nine of the studies in the review were controlled trials that compared vitamin B6 to a placebo.

The others were observational, meaning no treatment was given.

No significant cancer-lowering effect was seen in the nine controlled trials of vitamin B6.

This means that the role of vitamin B6 in preventing cancer is unclear.

And as a general rule, vitamin and mineral supplements are not recommended for cancer prevention as they may even increase the risk of cancer in some circ*mstances.

May Improve Heart Health

The role of vitamin B6 in heart health is also controversial.

Higher vitamin B6 intake has been associated with a lower risk of heart disease.

But taking vitamin B supplements has been determined to have little to no effect on survival, or risk of heart disease or stroke.

May Decrease Nausea and Vomiting of Pregnancy

Vitamin B6 is known to have anti-nausea properties. It's often used for nausea and vomiting of pregnancy, but there's limited data to support its benefits.

A study of 77 females found that vitamin B6 was better at decreasing nausea and vomiting during the first trimester than a placebo (sugar pill).

And a review of trials concluded that vitamin B6 was more effective than ginger for nausea and vomiting in pregnancy when it was taken for 60 days or longer.

Additional Uses

In addition to the above uses, vitamin B6 has been studied for the following conditions:

• Anxiety and depression
• Premenstrual syndrome
• Fibromyalgia
• Restless legs syndrome (RLS)
• Tardive dyskinesia
• Behavioral side effects of Keppra (levetiracetam)

So far, the evidence is fairly weak for B6 benefiting any of these conditions.

Vitamin B6 Deficiency

Some people may develop a B6 deficiency when:

• Intakes are lower than recommended levels over time.
• They have a specific risk factor for lower-than-normal levels.
• There's a reason they're unable to digest or absorb vitamin B6.

What Causes a Vitamin B6 Deficiency?

Vitamin B6 deficiency is uncommon in the United States.

It's usually found in tandem with low levels of other B-complex vitamins, such as niacin or folate.

Low levels of B6 can be caused by the following:

• Kidney diseases, including end-stage renal disease and chronic renal insufficiency (in which damaged kidneys can't filter out toxins from the blood as well)
• Problems with vitamin absorption, such as celiac disease, Crohn’s disease, or ulcerative colitis
• Genetic diseases like hom*ocystinuria (an inherited condition where the body can't process methionine, an amino acid)
• Long-term use of seizure medications

In cases of deficiency, particularly from a condition or depletion of B6 from a drug, supplementation may be required.

Groups at Risk of Vitamin B6 Deficiency

People with the following conditions are at higher risk for B6 deficiency:

• Kidney dialysis
• Critical illness
• Alcohol dependence
• Pregnancy
• Older age
• Recent surgery

How Do I Know If I Have a Vitamin B6 Deficiency?

Typically a vitamin B6 deficiency will be identified and diagnosed by a healthcare provider through specific labs.

However, some identifying features of a B6 deficiency may include the following:

• Microcytic anemia, characterized by fatigue
• Scaling or cracked lips or mouth (cheilosis)
• Swollen tongue (glossitis)
• Depression
• Confusion
• Seizures

What Are Side Effects of Vitamin B6?

Side effects are not common when vitamin B6 is consumed in foods, even in large amounts.

But taking high doses of vitamin B6 supplements over a long period can cause severe side effects like neuropathy (nerve pain) and ataxia (loss of coordination).

Nutrition

The National Institutes of Health (NIH) recommends the following daily amounts of vitamin B6.

As with most vitamins and minerals, these amounts vary depending on age, sex, and pregnancy or lactation (breastfeeding) status.