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Your Vitamin B6 status can impact your mood, your sleep, and your pain levels, not to mention your risk for all kinds of chronic illnesses. It is depleted by stress. This post is well worth a look if you have any stress in your life…

What is Vitamin B6?

B6 is a versatile vitamin with a multitude of functions. Because it is involved in so many enzymatic reactions, adequate levels are key for promoting and maintaining a healthy body. 

This post will delve into how B6 affects each sector of the body and the numerous benefits that it possesses.

“Vitamin B6” is a term that actually refers to six compounds in the body that work in a similar way.

The first three are:

  • pyridoxine (PN), an alcohol
  • pyridoxal (PL), an aldehyde
  • pyridoxamine (PM), which contains an amino group (R).

Their respective 5′-phosphate esters make up the remaining three:

  • Pyridoxal 5′ phosphate (PLP or P5P)
  • Pyridoxine 5′-phosphate (PNP)
  • Pyridoxamine 5′ phosphate (PMP) (R).

The human body cannot make vitamin B6 in any of its forms apart from dietary intake, so it is important to include foods rich in vitamin B6 as a part of your healthy diet.

Some foods high in vitamin B6 include beef, chicken, turkey, sunflower seeds, pistachios, and wild caught fish (especially tuna, salmon, halibut, and herring). Black cumin seed (Nigella sativa) is also a good source of B6 (R).

For some people, it may also be necessary to supplement with vitamin B6 (Pyridoxine HCl) or P5P.

Pyridoxal 5′ phosphate (PLP), otherwise known as P5P, can be found in supplement form as an alternative to taking B6 (pyridoxine). In a healthy body, the liver converts B6 to the active form, P5P. However, certain individuals may have difficulty making that conversion, and therefore may need to take vitamin B6 in its already active form: P5P.

B6 Snapshot


  • Very important for inflammatory conditions.
  • Improves IBS, Crohn’s, and Colitis.
  • Necessary for optimal cognitive function.
  • Improves sleep.
  • Decreases risk of cancers.


  • May interact with medications.
  • Excessive B6 supplementation may cause painful skin lesions, light sensitivity, and symptoms of digestive upset, such as nausea and heartburn.
  • Overdose over a long period (a year) can cause nerve damage.

Benefits of Vitamin B6 or Its Active Form, P5P

1) B6 is Beneficial for Inflammatory Conditions

Systemic inflammation is associated with decreased B6 status: Specifically, blood levels of P5P were 24% lower in individuals with the highest inflammation (R).

Low levels of B6 are associated with inflammatory conditions such as inflammatory bowel disease (IBD). Supplemental B6 can be used to manage the condition (R).

Low levels of the activated form of B6, P5P, in the bloodstream are associated with higher levels of the inflammatory marker, C-reactive protein (R).

Low B6 increases inflammation associated with cardiovascular disease (R).

Patients with Rheumatoid Arthritis tend to have low B6. Whether or not the deficiency was due to lack of supplementation, a 2005 study showed that taking supplemental B6 corrects the deficiency. However, it did not effectively help inflammation (R).

On the other hand, in 2010, a Taiwanese study of Rheumatoid Arthritis patients found that vitamin B6 supplementation at 100 mg/day suppressed IL-6 and TNF-alpha over a 3-month period. Blood levels of IL-6 remained significantly inversely related to blood levels of P5P (R).

B6 inhibits NF-κB activation (in mouse cells) (R).

B6 is also required for normal immune function (specifically, for CD8 T cells) (R).

2) B6 is Important for Digestive Health

A low intake of vitamin B6 is correlated with worse symptoms of IBS (R).

Patients with Inflammatory Bowel Disease (IBD) tend to have low B6. Supplements can be used to manage the condition (R).

3) B6 is Required for a Proper Histamine Response

B6 is required for the synthesis of Histamine (R).

Even though B6 helps form histamine, B6 also is important for normal functioning of diamine oxidase (DAO), the enzyme which breaks down histamine.

Intake of B6 could help lower histamine levels and benefit histamine intolerant patients (R).

4) B6 is Necessary for Optimal Brain & Nervous System Health

Low B6 is associated with Higher homocysteine levels, which can lead to brain damage (R, R2).

Even if a patient has high levels of homocysteine, research suggests that B6 supplements can still improve cognitive function (R).

However, there are no consistent results between B6 and a reduction in dementia (R, R2)

And there are no short-term benefits of B6 in terms of cognitive function, fatigue, and depression (R).

Deficiency in the Pyridoxal phosphate (P5P) form of B6 in the brain can cause neurological dysfunction, particularly epilepsy (R).

B6 can help alleviate symptoms of polyneuropathy, degeneration of peripheral nerves associated with diabetes and some types of Guillain–Barré syndrome (R).

5) B6 Helps You Sleep and Normalizes Sleep-Wake Cycles

A deficiency in B6 can cause sleep disturbances (R).

B6 seems to stimulate parts of the brain during rapid eye movement (REM) sleep, leading to seemingly more vivid dreams (R).

B6 can improve one’s awakening cortisol levels, which means that it’s easier for the brain to wake up to prepare for any anticipated stress (R).

A deficiency in the active form of B6, P5P, may cause tryptophan to be shunted toward the production of an organic acid called kynurenine, leading to low serotonin and melatonin, and causing sleep difficulties (R).

6) B6 is a Beneficial Agent for Anxiety

Taking a combination of B6 and magnesium supplements reduces PMS-associated anxiety (R, R2).

This combination is also effective when treating different forms of epilepsy that are characterized by depression or anxiety (R).

B6 deficiency is seen in those who have panic attacks or hyperventilation attacks (R).

Children with Autism (who often have anxiety) tend to have deficiencies in B6 and can be treated with the supplement (R).

7) B6 Deficiency Contributes to Depression

Low levels of B6 are significantly associated with symptoms of depression (R).

On the other hand, B6 was not an effective treatment for depression in a two-year study with older men (R).

Dopamine has been found to alter the requirements and storage mechanisms of B6, suggesting that excess dopamine can lead to B6 deficiency and in turn depression (R).

Women who take in more foods that contain B6 have lower chances of getting depression (R).

However, women who have post-pregnancy depression don’t show signs of B6 deficiency (R).

8) B6 Supports Weight Loss Efforts

A calorie-restricted diet enriched with cereal grains (rich in B6) can improve B6 levels. B6 levels also help maintain muscle mass during times of weight loss (R).

Supplemental B6 along with B12 for a long period of time results in overall less weight gain in obese men and women (R).

9) B6 Helps Reduce Pain

B6 is effective at reducing breast pain (cyclic mastalgia) (R).

B6 is also effective at relieving symptoms of carpal tunnel syndrome (R).

Migraines have been linked to B6 deficiency (R).

Vitamin B6 modulates Nitric Oxide in the cell, which is a mechanism by which deficiency causes vasodilation. Deficiencies in vitamins B6, B12 and folate result in less methylation, which can trigger a migraine (R).

10) B6 Reduces the Risk of Cancer

B6 may reduce the risk of cancer since it lessens inflammation, a major factor in the creation of cancer cells (R).

Those with cervical cancer have B6 deficiency (R).

Increased B6 intake decreased the risk of colorectal cancer (RR2).

11) B6 May Lower Risk for Cardiovascular Disease

A high intake of B6 and folate decreases the chance of dying from stroke, coronary heart disease, or heart failure in a Japanese population (R).

Dietary intake of B6 was associated with a reduced risk of coronary heart disease among middle-aged non-multivitamin supplement users (R).

In a study of 267 patients with coronary artery disease (CAD) and 475 healthy controls, higher levels of B6 (P5P) were correlated with lower levels of two indicators of systemic inflammation, C-reactive protein (CRP) and fibrinogen (R).

However, low B6 raises the risk of heart disease independent of inflammation status (R).

Studies have yet to show that supplemental vitamin B6 lessens inflammation in patients with cardiovascular disease (R).

Higher homocysteine levels are related to lower B6 levels (R), yet B6 is not effective at lowering the inflammation-causing homocysteine (R).

12) B6 is Helpful for Anemia

Vitamin B6 deficiency may lead to certain types of anemia (R).

13) B6 Helps Balance Blood Sugar

Deficiencies of B6 are common in those with type 2 diabetes (R).

A 6-week treatment with 150 mg/day of B6 lowered hemoglobin A1c levels (a measure of long-term blood sugar) in a study of 15 white men with type II diabetes (R).

B6 helps some cases of gestational diabetes as it increases glucose tolerance (R).

14) B6 Can Strengthen Bones

B6 deficiency leads to reduced neutrophils and lymphocytes resulting in bone marrow deficiency (in rats) (R).

Supplementation with B6 may reduce the incidence of hip fractures (RR2).

Decreased B6 status leads to lower bone mass density in patients with osteoporosis (R).

15) B6 is Important For Skin Health

B6 is key for skin development and maintenance (R).

Deficiency in B6 can lead to lesions as well as collagen deficiency, which maintains the skin’s elasticity (R, R2).

How Much B6 Do People Generally Need? (Dosage)

Institute of Medicine’s Food and Nutrition Board (FNB) Recommended Dietary Allowance (RDA) for Vitamin B6
Life Stage Age Males (mg/day) Females (mg/day)
Infants 0-6 months 0.1 ( AI ) 0.1 (AI)
Infants 7-12 months  0.3 (AI) 0.3 (AI)
Children 1-3 years 0.5 0.5
Children 4-8 years 0.6 0.6
Children 9-13 years 1.0 1.0
Adolescents 14-18 years 1.3 1.2
Adults 19-50 years 1.3 1.3
Adults 51 years and older 1.7 1.5
Pregnancy all ages 1.9
Breastfeeding all ages 2.0

Increasing Vitamin B6 Naturally

Some Dietary Sources of Vitamin B6 (R)

  • Beef liver: 0.9 mg per 3 oz serving
  • Sockeye salmon: 0.6 mg per 3 oz serving
  • Chicken breast: 0.5 mg per 3 oz serving
  • Turkey (meat only): 0.4 mg per 3 oz serving
  • Ground beef 86% lean: 0.3 mg per 3 oz serving

Vitamin B6 Deficiency

Those at Risk for Deficiency: 

  • People with poor kidney function (R).
  • Those with autoimmune disease, particularly rheumatoid arthritis (R) and disorders associated with poor absorption, including patients with celiac disease, Crohn’s disease, ulcerative colitis, and inflammatory bowel disease (R).
  • People with alcohol dependence (R).
  • People who routinely take non-steroidal anti-inflammatory drugs (NSAIDs) over 6 months’ time may have low B6 (R).

Safety of Vitamin B6

High intakes of vitamin B6 from food sources have not been reported to cause adverse effects (R).

However, taking 1-6 grams of B6 per day for more than a year can lead to severe neuropathy with loss of movement control (R).

The tolerable upper intake level set for adults is 100 mg per day (R).

Fortunately, symptoms usually go away after supplementation has been stopped. Other symptoms of excessive vitamin B6 supplementation includes painful skin lesions, light sensitivity, and symptoms of digestive upset, such as nausea and heartburn (R).

B6 Drug Interactions

Here are some medications that interfere with the metabolism of vitamin B6 or that are affected by B6 supplementation:

Broad-spectrum antibiotic Cycloserine (Seromycin®), used to treat tuberculosis, increases urinary loss of B6. This may worsen the seizures and neurotoxicity associated with cycloserine. (B6 supplements can help prevent these adverse effects) (R).

Antiepileptic Medications, including valproic acid (Depakene®, Stavzor®), carbamazepine (Carbatrol®, Epitol®, Tegretol®, and others), and phenytoin (Dilantin®) increase the breakdown rate of vitamin B6, resulting in low blood levels of P5P and high homocysteine. High homocysteine levels in antiepileptic drug users may increase the rate of seizures and stroke (R).

Anti-seizure medications phenytoin and phenobarbital may be reduced in the blood by B6 supplementation of 200 mg/day for 12–120 days (R).

COPD medications like Theophylline (Aquaphyllin®, Elixophyllin®, Theolair®, Truxophyllin®, et cetera) can cause low blood levels of P5P, which could cause seizures (R).

Non-steroidal Anti-inflammatory Drugs (NSAIDS) can lower blood levels of B6 (P5P), especially when taken chronically, over 6 months’ time (R).

Irregular Vitamin B6 Levels?

If you have not yet tested your Vitamin B6i levels, I recommend that you ask your doctor to do it. If you already have your blood test results and you’re not sure what to make of them, you need to check out Lab Test Analyzer. It does all the heavy lifting for you. No need to do thousands of hours of research on what to make of your various blood tests.

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  • Ann

    I also have Morton toe and many of the symptoms

  • TM

    Hi, is there a ratio to follow when giving both B6 and P5P? My son is on high dose (grams) of P5P before taking B6 lately. How do I know which works better?

  • Angela Berry-Koch

    My son has schizophrenia type symptoms and a positive dx for lyme (by culture). He was slightly high on pyrrole test many years back. But he was ART tested and did not tolerate P5P but was fine with regular B6. Still only a few times a week. Not regularly. I am trying to figure out why someone could not metabolize P5P which according to Klinghardt is 10 percent of the population? ? Thinking it may give me some hints on cause of the psychosis. I have wondered about porphyria because I have heard that these people cannot tolerate B6 very easily? Any wisdom on this appreciated, Angela

  • Joseph Arsanis

    If I am taking B6 300 mg plus B-Complex100 = 400 mg of b6 Daily for tardive dyskinesia and I changed over to P5P B6 how much would be the same? P5P is activated and b6 isn’t , so perhaps the same ?

  • Debra

    Can you take p5 p while tapering venlafaxine?

  • Sean Braughton

    Looks like I was doing this off the top of my head and replaced 12 with 6, but there are interesting studies to show that we should be limiting doses of most B vitamins as many of them tend to super dose us.

  • Eva v T

    My daughter have pyrrole and is also very high in histamine, she need B6 but I don’t dare give it to her due to that it increases histidine decarboxylase. What to do?

  • irais lec

    What about the max dosage for a 4 year old child with Autism of P5P?

  • Daniel Crawford

    Great write up. Though you are missing probably the most common related b6 issue.

    Pyrrole Disorder

    A common feature of many behavior and emotional disorders is pyroluria, an inborn error of pyrrole chemistry which results in a dramatic deficiency of zinc and Vitamin B-6. Common symptoms include explosive temper, emotional mood swings, poor short-term memory, and frequent infections. These patients are easily identified by their inability to tan, poor dream recall, abnormal fat distribution, and sensitivity to light and sound. The decisive laboratory test is analysis for pyrrole levels in urine. Treatment centers on normalizing blood levels of B-6 and zinc.

  • Terry

    Hi, Joesehph Cohen – Do you have any suggestions for people with naturally elevated B-6 levels? I don’t supplement it but my labs are at 223.4 with a reference range of 20.0 – 125.0 nmol/L (Pyridoxal 5-Phosphate). I’ve seen several forums with confused people like me who never take B-6 but are always high in serum labs. I wish I could say I feel great, but despite a good CRP level I still have some inflammation. In fact, I feel like I should be low in B-6. Thanks for any feedback, and for your excellent site.

    1. Bethany

      Do you by chance have Morton’s toe?
      I’m not a doctor, but I have Morton’s toe and I understand that genetically, we can have the problems you described.

  • Jing Xu

    It caught my attention that PL is an aldehyde, which is toxic. Can you explain more to us how PL is used and metabolized since I don’t see the benefit of it lingering inside body for long.


  • Nancy M

    Thank you for this interesting article. I am puzzled/frustrated by the fact that all of the supplements listed and those that I have found on the internet, far exceed the recommended dose mentioned. There are many references to P-5-P toxicity experiences found on the internet and yet you cannot but this in a dose below 25 mg. Jarrow B complex has it in 10 mg (closer to the 1 mg I am seeking for my child) but it has other vitamins that an individual may not be tolerant of.

    1. Joseph M. Cohen

      You should just use a b complex

    2. Daniel Crawford

      Sounds like you might have Pyrrole Disorder

      A common feature of many behavior and emotional disorders is pyroluria, an inborn error of pyrrole chemistry which results in a dramatic deficiency of zinc and Vitamin B-6. Common symptoms include explosive temper, emotional mood swings, poor short-term memory, and frequent infections. These patients are easily identified by their inability to tan, poor dream recall, abnormal fat distribution, and sensitivity to light and sound. The decisive laboratory test is analysis for pyrrole levels in urine. Treatment centers on normalizing blood levels of B-6 and zinc.

  • Eduardo

    I love everything you share. Can I make a suggestion? It would be great if you could let us know what the half lives of vitamins and other substances (like antioxidants) are, so we know whether we need to take them more than once a day. For instance, alpha lipoic acid has a really short half life. I tried to find this information about water soluble vitamins, but could not.

  • Brett

    I have some kind of weird B6 issue where my levels test rock-bottom (0) on a Organic Acids Test, despite making an effort to eat foods containing B6. I developed an insufficiency where the symptoms were this relentless “wired but tired” insomnia. I took the Source Naturals Coenzymated B6 (P5P) Sublingual lozenges – these were extremely potent, faster acting that swallowed tablets. I could feel a major serotonin rush within minutes of putting it under my tounge and I would fall right aslseep. After I built my levels up from regular use, they seemed to take on a more stimulating effect.

    1. Joseph M. Cohen

      This one?

  • daz

    thx for the post Joe,

    on the subject of b6 supps,
    I see that Country Life do another Active B6 supp,
    which is half p5p & half PAK (Pyridoxine alpha-ketoglutarate).

    could you comment on the PAK ingredient if possible

    1. Joseph M. Cohen

      I haven’t seen any studies on it…

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