Written by Slawomir (“Swavak”) Gromadzki, MPH

Vitamin B-6 (pyridoxine) is important for normal brain development and cognitive function, improving sleep and for keeping the nervous system and immune system healthy (decreases risk of cancers). Vitamin B6 is also very important for treating hormonal imbalance, IBS and inflammatory conditions including ulcerative colitis and Crohn’s disease. Because it is involved in so many enzymatic reactions, its normal levels are key for promoting and maintaining a general health.


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

  • Pyridoxine
  • Pyridoxal 5′ phosphate (P5P)
  • Pyridoxal
  • Pyridoxamine (PM) – contains an amino group
  • Pyridoxine 5′-phosphate (PNP)
  • Pyridoxamine 5′ phosphate (PMP)


Foods high in Vitamin B6 include sunflower seeds, pistachios, and black seed (Nigella sativa).


The following are associated with increased risk for Vitamin B6 deficiency:

  • Consuming low of vitamin B6 refined foods such as sugar, white flower products, white rice, use of stimulants, avoiding foods containing significant amount of Vitamin B6, chronic stress, etc.
  • Individuals with poor kidney function (R).
  • Those with autoimmune disease, particularly rheumatoid arthritis (R) and conditions associated with poor intestinal absorption, including coeliac disease, Crohn’s disease, ulcerative colitis, and other inflammatory bowel diseases (R).
  • People with alcohol dependence (R).
  • People on non-steroidal anti-inflammatory drugs (NSAIDs) (R).
  • Broad-spectrum antibiotic Cycloserine (Seromyci), used to treat tuberculosis, increases urinary loss of Vitamin B6. This may worsen the seizures and neurotoxicity associated with cycloserine. (B6 supplements can help prevent these adverse effects) (R).
  • Non-steroidal Anti-inflammatory Drugs (NSAIDS) can lower blood levels of B6 (P5P), especially when taken chronically, over 6 months’ time (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 frequency of seizures and stroke (R).
  • COPD medications like Theophylline (Aquaphyllin, Elixophyllin, Theolair, Truxophyllin, et cetera) can cause low blood levels of P5P, which could cause seizures (R).


Most common form of B6 found in supplements is Pyridoxine Hydrochloride (HCl). Better type of B6 is Pyridoxal 5-phosphate, known as P5P. It can be found in supplements as an alternative to taking B6 (pyridoxine).

Normally, in a healthy body, the liver converts Pyridoxine 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.



Apart from Magnesium (its deficiency is the most frequent cause of morning sickness) also 10-50 mg of Vitamin B6 and 15-50 mg of Zinc Citrate (must be citrate as other types of zinc may trigger nausea) are needed after breakfast as deficiencies of all of them (very common today) are believed to contribute to nausea during pregnancy.


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

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, R)

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).


A deficiency in B6 can cause sleep problems (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 the awakening cortisol levels, which means that B6 makes it easier for the brain to wake up to get ready for any anticipated stress (R).

In order to increase levels of serotonin, the strongest antidepressant hormone found in our body, you need to make sure you have enough Vitamin B6 as well as 5HTP (most bioavailable form of tryptophan), B1, B3 (Niacin), folic acid, magnesium, and zinc as all of them are required to produce this precious happy hormone. They all (including B6) are also important for normal levels of the key sleep hormone, melatonin, as melatonin is made in the body out of serotonin.

A deficiency of the active form of Vitamin B6, P5P, may cause tryptophan to be used in the production of an organic acid called kynurenine, leading to low serotonin and melatonin, thus contributing to depression and sleep difficulties (>).

5HTP in our liver is converted to 5HT, but it can be done only with the help of Vitamin B6. However, if you are even mildly deficient in this vitamin, liver will convert tryptophan to toxic metabolites rather than to 5-HT! It is therefore very important to always take 5-HTP with either Vitamin B6, B complex, or multivitamin which is contains at least 10mg of B6.


A combination of B6 and magnesium reduces PMS-associated anxiety (>, >).

The same two nutrients are also effective when treating different forms of epilepsy that are associated with depression or anxiety (R).

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

Children with Autism (who often suffer from anxiety) tend to be B6 deficient and can be treated with supplements containing this vitamin (R).


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).

B6 is required in the body to convert amino acid l-glutamine to the relaxing hormone known as GABA. L-glutamine is the precursor of GABA and therefore should increase its production. However, the conversion from glutamine to GABA requires vitamin B6 or P5P (the active form of this vitamin).


The most important nutrient for maintaining normal progesterone levels seems to be Vitamin B6. Vitamin B6 is absolutely essential for the development of the corpus luteum (a gland produced in the ovary after the egg is released) out of which progesterone is produced. Therefore, vitamin B6 is necessary for preventing progesterone deficiency and through progesterone for balancing other hormones including oestrogen.

That is the reason why B6, together with B5, Magnesium, D3 and Agnus castus (Vitex), are so effective in helping women with hormonal imbalance, menstrual problems, PMS > and other symptoms associated with low progesterone.

A group of British researchers suggest that taking daily dose of  100 to 200 milligrams of vitamin B6 may be very helpful in relieving PMS symptoms. According to the study women with PMS taking vitamin B6 supplements experienced significantly reduced PMS symptoms (such as depression) compared to the placebo group. In order to be more effective B6 supplements should be taken about seven days before menstruation. For the first two weeks of the cycle, it is recommanded to take about 100 mg of B6 daily with other B vitamins. Also keep in mind that the more vitamin B6 you is used, the more magnesium is needed. magnesium is also necessary to be used with vitamin D supplements.

Vitamin B6 alleviates depression associated with premenstrual syndrome >

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


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).


B6 is effective at reducing breast pain  known as 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).


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 (RR).


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).


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


Vitamin B6 plays important role in normal glycogen metabolism, preventing glycation, and regulating the release of stored glucose. In addition, vitamin B6, together with B12 and Alpha Lipoic Acid, helps in managing diabetic neuropathy.

Vitamin B6 helps in managing diabetic neuropathy and prevents glycation in which sugars react with proteins and fats in an abnormal way, producing harmful molecules. It can lead to cataract, kidney failure, and even Alzheimer’s.

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

A 6-week treatment with 150 mg/day of B6 lowered haemoglobin 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).


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 (RR).

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


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, R).


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.

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).


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

Patients with Inflammatory Bowel Disease (IBD) tend to be low in B6 and need Supplementation (R).


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).


In EU and UK the recommended daily intake of B6 for adults is 1.4 mg and in US 1.7mg.

Institute of Medicine’s Food and Nutrition Board (FNB) Recommended Dietary Allowance (RDA) for Vitamin B6

Infants            0-6 months     0.1

Infants            7-12 months   0.3

Children         1-3 years         0.5

Children         4-8 years         0.6

Children         9-13 years       1.0

Adolescents    14-18 years     1.2

Adults 19-50 years                 1.4

Adults 51 years and older     1.7

Pregnancy all ages                 1.9

Breastfeeding all ages          2.0


In the EU countries (including UK), the safe upper daily intake (SUL) for vitamin B6 (Pyridoxine) from supplements is set at 25mg for a long-term use and up to 200mg for a short-term.  In the US the SUL is 100mg. Intakes above 200 mg are not generally recommended except under medical supervision.


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

However, taking 1 to 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 include painful skin lesions, light sensitivity, and symptoms of digestive upset, such as nausea and heartburn (R).


– B6 helps absorption of niacin, riboflavin, folate & zinc.

– B6 enhances the uptake of magnesium and vice versa.    

– Vitamin B6 can inhibit the biosynthesis of thiamine (B1).

– High levels of B6 may increase the need for zinc.

– Vitamin B6 deficiency increases intestinal uptake of zinc but serum zinc levels decrease, demonstrating an impairment in zinc utilization.

– The amino acid taurine increases the communication and productivity of P5P (active form of Vitamin B6) and promotes the production of GABA.  Studies have shown that a deficiency of taurine can contribute to anxiety (>).


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

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



Any information or product suggested on this website is not intended to diagnose, treat, cure or prevent any medical condition. Never disregard medical advice or delay in seeking it because of something you have read on this website. Consult your primary healthcare physician before using any supplements or making any changes to your regime.