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Vitamin B6 is an essential dietary nutrient that is required to support nerve, skin, and red blood cell health.
It is involved in energy metabolism and is required for the synthesis of key neurotransmitters that regulate mood balance, alertness and sleep cycles. It is also important for myelin formation and brain health.
There are several different forms of Vitamin B6 supplements including pyridoxine HCL and Pyridoxal-5′-phosphate (P5P), sometimes referred to as Activated B6.
P5P is the active form of B6 in the body. It is critical for nutrient absorption from the gut and is an important coenzyme for converting carbohydrates, fats, and proteins into usable energy forms in our cells.
P5P also plays an important role in immune function for the production of antibodies. It also supports electrolyte balance and facilitates the release of stored glycogen from the liver and muscle tissue.
This article will discuss the available research on how vitamin B6 works in the body, common uses, health benefits, foods and supplements, safety and side effects, and possible interactions.
Mood
Brain Function
Weight Loss- >Supports mood balance and energy metabolism
- Important for nervous system function
- Supports healthy homocysteine levels
Top Vitamin B6 Products* ❯What is Vitamin B6?
Vitamin B6 is one of the eight B-complex vitamins. Pyridoxine is one of the most common forms of vitamin B6.
Although it is commonly used interchangeably with the name pyridoxine, the term “vitamin B6” technically refers to six separate compounds, called vitamers, which demonstrate B-complex activities.
In its coenzyme forms, vitamin B6 is involved in a diverse set of biological functions. It has roles in more than one hundred enzymatic reactions, the majority of which help to facilitate protein metabolism.
Vitamin B6 is a water-soluble vitamin and is only stored in minimal amounts in liver, muscle, and brain tissues. It is found in numerous food sources and deficiencies are rare in most developed countries. [1]
The University of Maryland Medical Center (UMM) reports that vitamin B6 is important in energy production, as are all B-complex vitamins.
The UMM states that all of the B vitamins are needed to maintain proper nervous system function and for keeping the liver, skin, hair, and eyes healthy. [2]
How Does Vitamin B6 Work Inside The Body?
The National Institutes of Health (NIH) states that the six vitamers of vitamin B6 are as follows:
- pyridoxine (PN), an alcohol
- pyridoxal (PL), an aldehyde
- pyridoxamine (PM), which contains an amino group
- pyridoxine-5′-phosphate (P5P)
- pyridoxal-5′-phosphate (PLP)
- pyridoxamine-5′-phosphate (PMP) [1]
Another form is 4-Pyridoxic acid (PA), which is a metabolite excreted in urine. Pyritinol is a semi-synthetic form of this vitamin that has been sold as a pharmaceutical drug in certain countries.
P5P is the most common form of this vitamin found in the blood. It is sometimes referred to as the active metabolite of pyridoxine. Most of these forms are interchangeable with each other in the body.
Vitamin B6 is required for the production of certain brain chemicals called neurotransmitters. In particularly, it is involved in the synthesis of norepinephrine, dopamine, and serotonin which are known to affect mood and concentration.
These chemical messengers help to convey communications between nerves inside the brain, in the central nervous system (CNS), and in the peripheral nervous system (PNS).
The NIH states that vitamin B6 is needed for proper brain development and function. It is essential for the formation of the myelin sheath that insulates nerves and improves signal transmission and speed.
Vitamin B6 is also necessary in the production of melatonin. This neurotransmitter/hormone is released by the pineal gland and influences functions including reproduction and sleep. [1]
Vitamin B6 acts synergistically with vitamins B9 (folate) and B12 (cobalamin) to modulate blood levels of a nonprotein amino acid called homocysteine. High levels of homocysteine may indicate heart disease. [1]
The NIH states that vitamin B6 is also necessary for normal magnesium and vitamin B12 absorption from the gut. This vitamin is involved in the production of gastric HCl or stomach acid.
Vitamin B6 is absorbed in humans in an area of the small intestine called the jejunum, which is located between the ileum and duodenum. [3]
Both vitamins B6 and B12 are needed to produce red blood cells and hemoglobin (compound that transports oxygen in red blood cells). This vitamin is also important for the production of immune system cells called lymphocytes.
Pyridoxine is needed for metabolism of amino acids, as well as lipid (fat) and protein metabolism.
Pyridoxine is converted into two coenzymes that are important in a large number of metabolic reactions. These are pyridoxamine phosphate and pyridoxal phosphate. [1]
According to the NIH some of the reactions these coenzymes are involved in include:
- Converting the amino acid tryptophan into vitamin B3 (niacin)
- Metabolism of phospholipids and polyunsaturated fatty acids
- Production of heme in hemoglobin
- Transferring amino acids from one molecule to another (transamination)
Because of its range of endogenous roles, current research on vitamin B6 is focused on how it might affect cardiovascular disease, cancer, neuropathy, metabolism, diabetes, depression, and more. [1]
Vitamin B6 Uses and Health Benefits
According to the Natural Medicines Comprehensive Database (NMCD) people take vitamin B6 supplements for a variety of uses including:
- Alzheimer’s disease
- Anemia
- Asthma
- Cardiovascular health
- Dysmenorrhea
- Homocystinuria
- Improving mood
- Keeping the blood vessels healthy
- Kidney stones
- Mood enhancement
- Nausea and vomiting during pregnancy
- Premenstrual syndrome (PMS)
- Protecting the health of the eyes
- Regulate sleep cycles
- Rheumatoid arthritis (RA)
- Supporting the function of the brain (nootropic) [3]
The NMCD rates Vitamin B6 as Effective for the treatment of hereditary sideroblastic anemia, pyridoxine-dependant seizures, and pyridoxine deficiency.
The NMCD also rates this vitamin as Likely Effective for decreasing excessive homocysteine levels in a condition called hyperhomocysteinemia. [3]
Vitamin B6 is rated as Possibly Effective for the following conditions:
- Age-related macular degeneration (AMD)
- Hyperkinetic cerebral dysfunction syndrome
- High blood pressure (hypertension)
- Nausea and vomiting during pregnancy
- Kidney stones (nephrolithiasis)
- Lung cancer
- Premenstrual syndrome (PMS)
- Tardive dyskinesia [3]
Vitamin B6 has also been studied for asthma, cancer, dysmenorrhea, and supporting heart health. While there have been some promising results in preliminary clinical trials, this research is limited at this time. [3]
More clinical trials are necessary to determine the therapeutic efficacy of vitamin B6 for these and other conditions.
The FDA has approved injectable vitamin B6 and a pyridoxine-doxylamine combination drug (Diclegis) as prescription medications for the treatment of morning sickness.
The FDA has not approved vitamin B6 dietary supplements as drugs for the prevention or treatment of any medical conditions. These products are sold to support the structure and function of the body, but cannot claim to improve any disease states.
Cardiovascular Health
Homocysteine is an amino acid intermediate that occurs during the metabolism of cysteine and methionine. [4]
Elevated homocysteine levels in the blood has been associated with low-grade chronic inflammation that can lead to blood vessel damage and heart disease.
Homocysteine in high levels can damage the endothelial tissue on the inside of blood vessels. As it builds up and causes damage to vessel linings, it encourages the formation of arterial plaque accumulations.
This plaque can cause the arteries to close off in a condition called atherosclerosis. [4] Atherosclerosis is the primary cause of coronary artery disease, which is the main cause of heart disease.
In more than one study, routine use of vitamin B6 supplements along with folate (vitamin B9) significantly reduced total homocysteine levels.
It is still not known if elevated homocysteine levels are a cause of cardiovascular disease or an effect of the disease. It is also not clear if lowering homocysteine levels results in a reduction of cardiovascular disease and deaths.
More research is needed to determine whether there is a therapeutic benefit for heart health linked to normalizing homocysteine measurements.
Some preliminary evidence suggests that B6 may support the regulation of lipids in the blood and blood pressure, two other factors that contribute to heart health. [4]
Anemia
Hemoglobin is a protein that transports oxygen in the blood. This protein is responsible for carrying oxygen molecules from the lungs throughout the body in red blood cells.
Vitamin B6 is needed to produce heme; the nonprotein part of hemoglobin. Without adequate B6, the body cannot make heme.
This can lead to symptoms like muscular aches, weakness, fatigue, and lethargy. Some studies have shown that ensuring adequate B6 not only helps to improve symptoms of certain types of anemia, but also inhibit its development in the first place. [3]
Currently, the NMCD states that vitamin B6 is Effective for hereditary sideroblastic anemia. In this treatable and reversible condition, red blood cells called erythroblasts are unable to produce sufficient hemoglobin.
More research is still required to determine the effects of vitamin B6 on other types of anemia.
Brain Function
Research has shown that being deficient in vitamin B6 can affect memory function especially with age, which may possibly contribute to the development of cognitive impairment in conditions like dementia and Alzheimer’s disease. [3]
This may have something to do with vitamin B6 regulating homocysteine levels in the blood. Homocysteine accumulations can also cause damage to nerve cells, possibly causing neurons in the brain to function poorly.
Vitamin B6 is also needed for the production of neurotransmitters that affect the mood, the ability to concentrate, and mental energy.
Some researchers believe that B6 might benefit children with ADHD (attention deficit hyperactivity disorder) and/or other conditions that affect learning capacities and attention span. [3]
At this time, the research using vitamin B6 for Alzheimer’s disease, autism, and cognitive function has not shown improvements in these conditions. [3]
Concerning ADHD, the effects of vitamin B6 have not been studied enough to make any determinations about efficacy.
While it is sometimes used as a nootropic, more research is needed to determine what effects vitamin B6 supplementation may have on cognitive function and mental performance.
Depression and Mood
Vitamin B6 affects levels of the neurotransmitters serotonin, dopamine, and norepinephrine in the brain. Very small changes in the levels of these chemicals can cause significant changes in mood, fatigue, pain, and anxiety.
Because of this, proper levels of vitamin B6 in the body are associated with improving state of mind and enhancing the mood. [1]
The NMCD states that, “Preliminary clinical research suggests that taking pyridoxine may reduce symptoms of depression in postmenopausal women but not to the general population.”
Additionally, some preliminary clinical research suggests that vitamin B6 supplementation may have a positive impact on dysphoric mental states.
More research is needed to determine what effects pyridoxine may have on mood enhancement and mood disorders.
Nausea In Pregnancy
Research has shown that in pregnant women, 25 mg vitamin B6 doses every 8 hours for at least 72 hours can decrease nausea and vomiting associated with morning sickness.
Benefits are most prominent in those with severe symptoms, and not as strong in those with only mild or moderate symptoms. [3]
According to the American College of Obstetrics and Gynecology, Vitamin B6 is considered a first-line treatment for vomiting and nausea induced by pregnancy. It is typically used alone first as a dietary supplement to see if symptoms improve.
In cases where pyridoxine alone is not effective, an FDA-approved prescription pyridoxine-doxylamine product called Diclegis (Dilectin in Canada) is sometimes prescribed.
Diclegis is most commonly used in moderate cases of morning sickness and cases of hyperemesis gravidarum (HG).
HG is a severe form of morning sickness that causes excessive nausea and vomiting which may lead to weight loss and dehydration, and sometimes requires hospitalization.
Eye/Vision health
B-complex vitamins are generally associated with improved vision and eye health. Taking B6 along with folate and other B vitamins can help to maintain vision with aging and avoid various common eye disorders.
The NMCD states that in one large study, 50 mg/day doses of pyridoxine used with 1000 mcg/day vitamin B12 and 2500 mcg/day vitamin B9 significantly decreased the risk for developing age related macular degeneration in women. [3]
In this study, women at least 40 years of age with histories of cardiovascular disease were given the above combination for an average of 7.3 years. Risk for developing AMD was reduced by 34% on average. [3]
Research continues to explore how B-complex vitamins work synergistically to protect the health of the eyes and avoid vision loss.
Kidney Stones
Some evidence from a number of research studies suggests that vitamin B6, alone or with magnesium, can reduce oxalate levels in urine in those with a hereditary kidney stone-causing disorder called type 1 primary hyperoxaluria. [3]
However, the NMCD states that B6 does not seem to be helpful for other conditions where kidney stones develop.
In one small study, women with no history of kidney stone formation who took high doses of B6 decreased their risks of developing kidney stones. This result has not been duplicated in men. [3]
More research is still needed to determine whether Vitamin B6 supplementscan improve kidney stones in either sex.
Vitamin B6 Deficiency
Vitamin B6 deficiency is rare among people who eat a healthy and nutritious diet.
Deficiencies may occur in those with elevated blood urea levels in the kidneys (uremia), liver cirrhosis, nutrient malabsorption disorders, alcoholism, pregnant women, congestive heart failure, and/or hyperthyroidism.
Deficiency is also more likely in those taking certain types of prescription drugs.
The Natural Medicines Comprehensive Database reports that pyridoxine deficiency in adults mainly affects mucous membranes, peripheral nerves, skin and the hematopoietic system (blood making organs). B6 deficiency in children can also affect the CNS. [3]
Some symptoms of B6 deficiency to look for include generalized seizures, abnormal electroencephalogram readings, weakness, dizziness, inflammation, irritability, confusion, and depression.
Other symptoms include swelling and redness on the tongue and/or ulcers or sores on the mouth, particularly in the corners of the mouth.
Vitamin B6 Food Sources
Vitamin B6 is found in numerous food sources in small amounts. Some of the best food sources of vitamin B6 include:
- Wheat Germ
- Bananas
- Sunflower Seeds
- Lentils
- Beans
- Legumes
- Brown Rice
- Liver
- Salmon
- Shrimp
- Tuna
- Turkey
- Chicken
- Milk
- Cheese
Green leafy vegetables like spinach, chard, kale, and dandelion greens also provide decent amounts of vitamin B6. Some fortified cereals and other grain products also contain this important nutrient.
If possible, choose organic produce sources. If you eat meats, consider choosing grass-fed organic meats that are free of antibiotics, steroids, and growth hormones.
When possible, it is recommended to obtain necessary nutrients like vitamin B6 from food sources.
For some people with certain medical conditions or life circumstance this is not possible. In these cases, supplementation may be useful.
Vitamin B6 Supplements
The University of Michigan Medical Center states that vitamin B6 supplements are available as softgels, tablets, chewable gummies, liquid drops, capsules, and lozenges.
The most common formulations of pyridoxine come in 25 mg, 50 mg, and 100 mg dosages.
According to the NMCD, that there are more than 19,000 dietary supplement products available commercially that contain B6 either alone or with other compounds.
It is commonly listed on labels as pyridoxal, pyridoxamine, pyridoxine hydrochloride, and pyridoxal-5-phosphate.
Vitamin B6 Dosage
The UMM reports the following recommendations for dietary (food-derived) vitamin B6 daily intake: [2]
- 0.1 mg/day for infants 0 to 6 months of age
- 0.3 mg/day for infants between 7 and 12 months
- 0.5 mg/day for children between 1 and 3 years
- 0.6 mg/day for children between 4 and 8 years
- 1 mg/day for children between 9 and 13 years
- 1.3 mg/day for boys between 14 and 18 years
- 1.2 mg/day for girls between 14 and 18
- 1.3 mg/day for men and women between 19 and 50
- 1.7 mg/day for men over 50
- 1.5 mg/day for women over 50
- 1.9 mg/day for pregnant women
- 2.0 mg/day for women during breastfeeding
The recommended daily maximum intake for adults is 100 mg per day. Dosages higher than this should be discussed with a doctor.
When used as a dietary supplement typical dosages range between 25-100 mg per day.
In research studies, the following dosages have been studied:
- Anemia: 25 mg/day in combination with other vitamins
- Cardiovascular disease: 40 mg/day
- Cognitive function: 20 mg/day for 12 weeks
- Dysmenorrhea: 200 mg/day
- PMS: Up to 600 mg/day; suggested optimal dosage is 100 mg/day [2]
The UMM states that while larger doses of vitamin B6 have been studied, doses above 100 mg/day should not be used without the advice and supervision of a medical professional.
Excessive doses of pyridoxine can cause nerve dysfunction or disease (neuropathy). [2]
Vitamin B6 Side Effects
The NMCD rates Vitamin B6 as Likely Safe for healthy adults when appropriately taken orally, parenterally, or in injectable form. Injectable vitamin B6 is a prescription medication and can only be administered by a doctor. [3]
The NMCD rates pyridoxine as Likely Safe when used orally and appropriately by pregnant or breastfeeding women. However, it is recommended that it not be used long-term or without a doctor’s supervision and guidance on dosage. [3]
Vitamin B6 taken at appropriate dosages is generally well tolerated by most people. Although side effects are unlikely, some adverse reactions reported include:
- loss of appetite
- sleepiness
- stomach pain
- nausea
- vomiting
- paresthesia (tingling or numbness normally felt in the limbs)
- allergic reactions [3]
Breast tenderness (mastalgia), breast enlargement, sensitivity to light, certain skin disorders, and decreased levels of serum (blood) folate are also possible.
More serious side effects such as neuropathy are also possible but are unlikely with normal serving sizes. These dangerous outcomes are typically associated with high doses over a long period of time.
Vitamin B6 Drug Interactions
Vitamin B6 can interact with certain prescription medications and its absorption can be significantly affected by other medications and some herbal supplements.
Talk with your doctor before using vitamin B6 supplements together with antibiotics like cycloserine, antiepileptic medications like valproic acid, antihypertensive drugs like captopril, and antiasthmatic drugs like theophylline.
The NMCD recommended caution when taking vitamin B6 along with herbs with blood-pressure lowering potential including:
- Andrographis
- Casein peptides
- Cat’s claw
- Coenzyme Q10
- Fish oil
- L-arginine
- Lycium
- Stinging nettle
- Theanine [3]
Other interactions are possible. If you are interested in taking vitamin B6 supplements, consult with a doctor to determine if this product is appropriate for you.
- National Institutes of Health. Office of Dietary Supplements. Vitamin B6 Dietary Supplement Fact Sheet. Accessed Dec. 20, 2016.
- University of Maryland Medical Center. Vitamin B6 (Pyridoxine). Accessed Dec. 20, 2016
- Natural Medicines Comprehensive Database. Vitamin B6 Monograph. Accessed Dec. 20, 2016.
- Axe, J. Vitamin B6 Benefits, Deficiency & Sources. Accessed Dec. 20, 2016.
Article last updated on: June 23rd, 2018 by Nootriment