Pyridoxine (Vitamin B6) Uses, Benefits, Dosages, Side Effects & Dangers of Too Much

Pyridoxine is the most common form of Vitamin B6 found in foods and in dietary supplements.

This vitamin plays important roles in metabolism, the synthesis of red blood cells, brain function, blood sugar regulation, the immune system and in nerve signaling.

Pyridoxine has some unique roles relative to other B-complex vitamins. While all members of the vitamin B family are used to convert carbohydrates to usable energy in the body, pyridoxine is also important in producing brain chemicals called neurotransmitters.

It is also needed to synthesize a pineal gland hormone, called melatonin which is believed to be largely responsible for regulating the sleep/wake cycle.

Like other B vitamins, pyridoxine is important for maintaining healthy liver, skin, hair and eyes. It is also necessary for keeping the nervous system functioning properly. [1, 2]

This article reviews what pyridoxine is, how it works inside the body, its health roles, recommended dosages, food sources, supplement forms, safety, side effects, and interactions.

Pyridoxine

Vitamin B6 Supplement

Mood

Brain Function

Weight Loss

How It Works:

• >Supports mood balance and energy metabolism
• Important for nervous system function
• Supports healthy homocysteine levels

Dosage:

Between 25 - 100 mg per day

Safety:

Rated Likely Safe

Top Vitamin B6 Products* ❯

View User Ratings* ❯

What is Pyridoxine?

The molecular formula of pyridoxine is C8H12ClNO3.

According to the Human Metabolome Database (HMDB), “Although pyridoxine and Vitamin B6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading.” [3]

They note that pyridoxine is one of several different compounds that can be called vitamin B6, but it is not the only form of this vitamin.

The Natural Medicines Comprehensive Database (NMCD) states, “Several forms of vitamin B6 exist, including pyridoxine, pyridoxal, and pyridoxamine. All of these forms are considered to be equivalent in the human body.” [2]

One form of pyridoxine, called 4-methanol, can be converted into PLP (pyridoxal 5′-phosphate). In turn, PLP is used as a coenzyme in synthesizing amino acids, aminolevulinic acid, neurotransmitters including serotonin and epinephrine (adrenaline), and sphingolipids. [3]

According to Medscape, “Pyridoxine 5′-phosphate, vitamin B-6, is an essential cofactor in various transamination, decarboxylation, glycogen hydrolysis, and synthesis pathways involving carbohydrate, sphingolipid, amino acid, heme, and neurotransmitter metabolism.” [5]

Because it is water-soluble, pyridoxine is largely and quickly eliminated via urine and feces. However, the body does store some vitamin B6 mainly in the liver, but also in muscle and brain tissues. [4]

As a dietary supplement, this vitamin is typically provided in the form of Pyridoxine Hydrochloride (HCl).

PubChem states, “Pyridoxine Hydrochloride is the hydrochloride salt form of pyridoxine, a water-soluble vitamin B.” [4]

How does pyridoxine work inside the body?

According to the NMCD and the HMDB, pyridoxine is necessary for:

• Amino acid, carbohydrate, and lipid metabolism
• Hormonal balance
• Keeping potassium and sodium levels balanced
• Production of various neurotransmitters
• Proper immune system function
• Red blood cell production
• Reducing homocysteine levels
• Skin health [2, 3]

In the body, vitamin B6 is converted into the coenzyme pyridoxal phosphate. This compound is necessary for many different metabolic functions in the body.

Some of the roles of this coenzyme including amino acid breakdown, converting tryptophan to vitamin B3 (niacin), and the synthesis of neurotransmitters in the central nervous system, including serotonin, epinephrine, dopamine, and GABA.

Pyridoxine is involved in the regulation of homocysteine levels in the blood. Homocysteine is a homologue of the alpha amino acid, cysteine. High levels of homocysteine are associated with increased risks for heart disease. [1]

The University of Maryland Medical Center (UMM) states, “Along with vitamins B12 and B9 (folic acid), B6 helps control levels of homocysteine in the blood.” [1]

The UMM states that pyridoxine helps cells better absorb cyanocobalamin (vitamin B12). It also helps to manufacture immune system cells and promotes red blood cell production. [1]

Additionally, vitamin B6 is necessary for the production of heme, a component of hemoglobin. Hemoglobin is the compound in red blood cells that carries oxygen from the lungs to body tissues. [3]

Uses for Pyridoxine Supplements

Like other B-complex vitamins, pyridoxine supplements has manve oral (by mouth) uses. The NMCD reports that people have used this nutrient for:

• Dental decay during pregnancy
• Depression associated with pregnancy or oral contraceptive use
• Depression in postmenopausal women
• Dysmenorrhea (painful menstruation)
• Morning sickness during pregnancy
• Nausea or headache associated with oral contraceptive use
• Nausea and vomiting in children with enteritis
• PMS (premenstrual syndrome)
• Pyridoxine deficiency [2]

Pyridoxine is also used orally for hyperhomocysteinemia, Alzheimer’s disease, cognitive impairment, boosting immunity, cancer, arthritis, allergies, and ADHD (attention-deficit hyperactivity disorder). [2]

Vitamin B6 is also taken by mouth for migraine headache, various skin conditions, blood-lipid imbalance, poor appetite, high blood pressure, atherosclerosis, and improving dream recall. [2]

The NMCD lists dozens of other uses for this vitamin. At this time research on these uses is limited and consists primarily of in vitro and animal studies.

While there is a significant amount of research on the endogenous roles of this vitamin in the body, less is known about how it works when used as a dietary supplement. Many of its purported uses as a supplement lack substantiation from clinical trials.

Evidence from research on pyridoxine’s health benefits will be reviewed below. [2]

Seek medical advice before taking Vitamin B6 supplements to promote a specific health goal.

Pyridoxine Health Benefits

The Natural Medicines Comprehensive Database has rated pyridoxine as Effective for hereditary sideroblastic anemia, pyridoxine-dependent seizures, and Vitamin B6 deficiency. [2]

The NMCD has also rated pyridoxine as Likely Effective for treating postprandial (after-meal) hyperhomocysteinemia (elevated homocysteine levels). [2]

The NMCD rates pyridoxine as Possibly Effective for:

• Age-related macular degeneration (AMD)
• Atherosclerosis (“clogged” arteries)
• Nephrolithiasis (kidney stones)
• Pregnancy-induced nausea and vomiting
• Premenstrual syndrome (PMS)
• Tardive dyskinesia [2]

Pyridoxine continues to be studied for its possible benefits in depression, heart disease, RA (rheumatoid arthritis), diabetes, stroke, high blood pressure, several types of cancer, and more. [2]

While promising results have come out of some studies on other uses, more research is still needed to determine the therapeutic efficacy of pyridoxine for these uses.

It is best to talk with your doctor if you are interested in using a pyridoxine supplement to address a specific health concern. This supplement has not been approved as a drug by the FDA for the prevention or treatment of any medical conditions.

Cardiovascular Health

Pyridoxine is sometimes taken for cardiovascular health and circulatory function.

There is some evidence that a combination of B complex vitamins, including vitamin B6, may reduce the risk of vascular related deaths in patients who have had a previous stroke or heart attack and are not taking antiplatelet medication.

Pyridoxine is sometimes taken for heart health because of its ability to lower homocysteine

levels. However it is still not known if elevated homocysteine levels are a cause of vascular disease or an effect and it is not clear if lowering these levels results in reduced cardiovascular disease or death. More research is needed in this area.

Mood Enhancement

Because pyridoxine has been shown to affect the production of neurotransmitters like serotonin and GABA in the brain, some people take it to enhance their mood.

Some preliminary clinical research suggests that taking vitamin B6 may have a favorable impact on dysphoric mental states. Other research has shown that it may reduce symptoms of depression in postmenopausal women.

More research is still needed to understand the effect vitamin B6 may have on mood enhancement.

Pregnancy-Related Conditions

Pyridoxine supplementation is considered a first-line treatment for the nausea and vomiting associated with pregnancy (“morning sickness”) by the American College of Obstetrics and Gynecology. [2]

There is an FDA-approved prescription pyridoxine product available known as Diclegis (Diclectin in Canada) that is used to relieve moderate morning sickness and hyperemesis gravidarum (severe nausea and vomiting that can cause weight loss and dehydration).

It also contains the sleep-inducing antihistamine doxylamine.

Some preliminary clinical research has found that pyridoxine supplementation may improve glucose tolerance and blood glucose levels in pregnant women with gestational diabetes and vitamin B6 deficiency.

This result may have been due to changes in diet, as other research did not observe this effect. More research is still needed in this area.

Pyridoxine Deficiency

Pyridoxine deficiency is very rare in the US and Canada. According to Medscape, “Acquired deficiency is associated with inflammatory disorders and with concurrent use of several medications.” [5]

Certain groups of people are more at risk of developing vitamin B6 deficiency including elderly people, people who are severely malnourished, people with inflammatory conditions, people with liver and kidney conditions, alcoholics, smokers, and pregnant women. [5]

The Human Metabolome Database states that, “Deficiency, though rare because of widespread distribution in foods, leads to the development of peripheral neuritis in adults and affects the central nervous system in children.” [3]

Vitamin B6 deficiency can cause changes in the nervous system, skin, and blood. Both deficiency as well as excessive consumption of this vitamin can cause peripheral neuropathy (nerve dysfunction/disease). [5]

Symptoms of low levels of pyridoxine include weakness, dizziness, inflammation, numbness in distal limbs (hands, feet, lower legs), fatigue, anemia, depression, confusion, anorexia, and vomiting. [5]

The NMCD states that oral administration of this vitamin prevents and treats its deficiency effectively. [2]

Pyridoxine Foods and Supplements

Pyridoxine is found in numerous foods, and can be gained in adequate amounts through the diet in most cases.

Some of the best sources are brewer’s yeast, wheat germ, whole grain foods, enriched bread and cereal, organ meats, dark-green leafy vegetables, sunflower seed, banana, cheese, milk, fowl and fish. [1]

Most people who eat a diverse and healthy diet do not need supplemental amounts to prevent deficiency. However, there are cases where dietary intake of pyridoxine is insufficient and a supplement may be useful.

The UMM reports that supplements are sold under several names including pyridoxal-5-phosphate, pyridoxine hydrochloride, pyridoxal, and pyridoxamine. It is available in tablet, capsule, soft gel, lozenge, and other forms. [1]

There are a variety of dosages of vitamin B6 supplements available able with the most common formulations being 25mg, 50mg, and 100mg.

The NMCD reports that there are currently more than 19,000 different dietary supplements on the market that contain this ingredient alone or in combination with other compounds.

The quality of these products varies and it is recommended to do your research and find high quality supplements. It is important to read product labels carefully to ensure you are getting what you are looking for. [2]

When possible, look for organic, non-GMO, toxin-free supplements that are not manufactured with unnecessary fillers.

B vitamins are destroyed by heat, light, and air. Keep pyridoxine supplements in dark locations, in airtight containers at room temperature.

Pyridoxine Dosage

The UMM reports the following RDAs (recommended daily allowances) for pyridoxine: [1]

• 0.1 mg (adequate intake) for infants 0-7 months of age
• 0.3 mg (AI) for infants 7-12 months
• 0.5 mg (RDA) for children 1-3 years of age
• 0.6 mg for children 4-8 years
• 1 mg for children 9-13 years
• 1.2 mg for girls between 14-18 years
• 1.3 mg for boys between 14-18 years
• 1.3 mg for women and men between 19-50 years
• 1.5 mg for women 50 years and older
• 1.7 mg for men 50 years and older
• 1.9 mg for pregnant women
• 2.0 mg for women while breastfeeding

The recommended daily maximum intake for adults, pregnant, and lactating women over 18 is 100 mg per day. Dosages higher than this should be discussed with a doctor.

When used as a dietary supplement, dosages typically range from 25-100 mg per day.

In a study on cardiovascular disease and hyperhomocysteinemia, dosages of 40 mg per day were given to patients. One study on cognitive function gave patients 20 mg daily for 12 weeks.

In research on PMS, dosages as high as 600 mg per day have been used. However multiple studies have suggested 100 mg daily as the optimal level because of the potential for more side effects at higher dosages. [2]

According to the UMM, “Larger doses have been used in some studies. But you should not take doses above 100 mg per day without a doctor’s supervision.” [1]

Taking too much of this vitamin can result in nerve damage. Dosages of higher than 200 mg per day could result in neurological disorders including problems with balance and loss of sensation in the legs.

Pyridoxine Safety and Side Effects

The Natural Medicines Comprehensive Database rates pyridoxine as Likely Safe when used orally or parenterally and appropriately. [2]

Oral supplements are available for use without a prescription. Injectable vitamin B6 is an FDA-approved prescription medication and must be administered by a doctor. [6]

If you are pregnant or planning to be, speak with your doctor about using pyridoxine first. The NMCD rates vitamin B6 as Likely Safe during pregnancy and breastfeeding. Pyridoxine is commonly used for relieving symptoms of morning sickness.

During pregnancy it is recommended to speak with your doctor to help determine the best dosage for your needs, and to determine if supplemental pyridoxine is sufficient or if a stronger prescription product like Diclegis is necessary. [2]

Excessive doses have been rated as Possible Unsafe during pregnancy because there is concern that high dosages may cause seizures in newborns, however the mechanism of this is not well understood at the moment. [2]

This vitamin does pass into breast milk. It is possible that too much pyridoxine may harm a breastfeeding baby. [6]

There is also some evidence that very high dosages may reduce breast milk production. Speak with your doctor about appropriate dosages while breastfeeding.

The NMCD rates vitamin B6 as Likely Safe for use in children when used orally and appropriately, and Possibly Safe when used orally in dosages that exceed the RDA. It is recommended to seek medical advice about giving supplemental pyridoxine to children. [6]

According to the NMCD and University of Michigan Medical School, most people tolerate this supplement well and do not experience adverse effects.

Common mild side effects include headache, nausea, vomiting, abdominal pain, heartburn, loss of appetite, drowsiness, or mild tingling sensations. [2, 6]

Seek medical assistance right away if you notice:

• Chronic tiredness
• Decreased sensation to touch, temperature, and vibration
• Difficulty breathing
• Loss of balance or coordination
• Numbness in your feet or around your mouth
• Swelling of your face, lips, tongue, or throat [6]

Other side effects are possible when taking a pyridoxine supplement, especially if you use high dosages for long periods of time or take an overdose.

It is always recommended that you speak with your doctor before beginning any new supplements, especially if you are taking any prescription medications or have a preexisting medical condition. [6]

Talk to your doctor first about using a pyridoxine supplement if you have heart disease, diabetes, or kidney disease. [6]

Pyridoxine Drugs Interactions

Population research in women suggests that high pyridoxine intake is associated with increased risk for developing colorectal cancer. It is not clear why this is the case.

The NMCD states, “Vitamin B6 (pyridoxine) intake at a median dose of 1.63 mg daily is associated with a 3.6-fold increased risk of rectal cancer compared to a median intake of 1.05 mg daily.” [2]

This data comes from an epidemiological (population-based) study. While it establishes evidence of a correlation, it does not necessarily provide evidence of causation. More study is required to understand the potential risk.

Using a pyridoxine supplement along with antihypertensive medications may lower blood pressure dangerously.

Seek medical advice and use extra caution if using this supplement with drugs that affect blood pressure including:

• captopril (Capoten)
• enalapril (Vasotec)
• losartan (Cozaar)
• valsartan (Diovan)
• diltiazem (Cardizem)
• amlodipine (Norvasc)
• hydrochlorothiazide (HydroDiuril)
• furosemide (Lasix)
• Many others [2]

Be careful using pyridoxine along with herbs and supplements with blood pressure lowering effects. Some supplements that can influence blood pressure include:

• Andrographis
• Casein Peptides
• Cat’s Claw
• Coenzyme Q10
• Fish Oil
• L-Arginine
• Lycium
• Stinging Nettle [2]

Antibiotics, cycloserine (Seromycin), estrogens, isoniazid (INH, Rifamate), penicillamine (Cuprimine), and theophylline (Theochron, Theolair, and others) may affect the absorption of pyridoxine. [2]

This vitamin may affect results on laboratory tests that measure urobilinogen. [2]

As with most supplements, it is recommended to stop using pyridoxine supplements at least two weeks before you are scheduled for any type of surgery. [2]

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