Vitamin B6 is an essential nutrient needed by nerves, skin and red blood cells. It is one of eight B Group vitamins. Pyridoxine is one of the most common forms of vitamin B6.
It is involved in the metabolism of energy 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 vitamin B6 supplements, including pyridoxine HCL and pyridoxal-5′-phosphate (P5P), sometimes called activated B6.
P5P is the active form of B6 in the body. It is essential for the uptake of nutrients from the gut and is an important coenzyme for the conversion of carbohydrates, fats, and proteins into beneficial energy forms in our cells.
P5P also plays an important role in immune function in the production of antibodies. It also maintains electrolyte balance and facilitates the release of stored glycogen from liver and muscle tissue.
This article will discuss the available research on how vitamin B6 works in the body, general uses, health benefits, foods and supplements, safety and side effects, and potential drug interactions.
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What is Vitamin B6?
Although commonly used interchangeably with the name pyridoxine, the term “ vitamin B6 ” technically refers to six separate compounds called vitamins that indicate group B vitamin complex.
In coenzyme forms, pyridoxine is involved in a variety of biological functions. It has over a hundred enzymatic reactions, most of which help to facilitate protein metabolism.
Vitamin B6 is a water-soluble vitamin and is only stored in minimal amounts in the liver, muscles and brain tissue. It is found in many food sources and you will not find this vitamin deficiency in many developed countries.
According to the University of Maryland Medical Center (UMM), pyridoxine is important for energy production, as are all B-complex vitamins.
UMM states that all B vitamins are needed to maintain the proper function of the nervous system and to maintain healthy liver, skin, hair, and eyes.
How Does Vitamin B6 Work Inside The Body?
The National Institute of Health (NIH) states that six forms of vitamin B6 are:
- pyridoxine (PN), alcohol
- pyridoxal (PL), aldehyde
- pyridoxamine (PM), which contains an amino group
- pyridoxine-5′-phosphate (P5P)
- pyridoxal-5′-phosphate (PLP)
- pyridoxamine-5′-phosphate (PMP)
Another form is 4-pyridoxic acid (PA), which is a metabolite excreted in the urine. Pyritinol is a semi-synthetic form of this vitamin that has been marketed as a drug in certain countries.
P5P is the most common form of this vitamin in the blood. This is sometimes called the active metabolite of pyridoxine. Most of these shapes are interchangeable with the body.
Vitamin B6 is required for the production of certain brain chemicals called neurotransmitters. In particular, he is involved in norepinephrine, dopamine and serotonin synthesis, which is known to affect mood and concentration.
These chemical signals help to communicate between the nerves in the brain, the central nervous system (CNS) and the peripheral nervous system (PNS).
The NIH states that pyridoxine is required for proper brain development and function. It is necessary to create a myelin sheath that isolates the nerves and improves signal transmission and speed.
Vitamin B6 is also required for the production of melatonin. This neurotransmitter/hormone is produced by the pineal gland and affects functions including reproduction and sleep.
Vitamin B6 works synergistically with vitamins B9 (folate) and B12 (cobalamin), which modulates the amount of an amino acid in the blood called homocysteine. High levels of homocysteine can indicate heart disease.
The NIH states that vitamin B6 is also required for normal intestinal absorption of magnesium and vitamin B12. This vitamin is involved in the production of stomach acid.
Vitamin B6 is absorbed in the small intestine, called the jejunum, which is located between the ileum and the duodenum.
Both vitamin B6 and B12 are needed to produce red blood cells and hemoglobin (a compound that transports oxygen to red blood cells).e in blood cells). This vitamin is also important for the production of immune cells called lymphocytes.
Pyridoxine is required for amino acid metabolism as well as lipid (fat) and protein metabolism.
Pyridoxine is converted into two coenzymes that are important for many metabolic reactions. These are pyridoxamine phosphate and pyridoxine phosphate.
According to the NIH, some of these coenzyme reactions are:
- Conversion of the amino acid tryptophan to vitamin B3 (niacin)
- Metabolism of phospholipids and polyunsaturated fatty acids
- Heme production of hemoglobin
- Transfer of amino acids from one molecule to another (transamination)
Due to its endogenous role spectrum, current research on pyridoxine focuses on how it can affect cardiovascular disease, cancer, neuropathy, metabolism, diabetes, depression, etc.
Vitamin B6 Consumption And Health Benefits
According to the Natural Medicines Comprehensive Database (NMCD), people use vitamin B6 supplements for a variety of purposes, including:
- Cardiovascular Health
- Improve your mood
- Keep your blood vessels healthy
- With kidney stones
- Nausea and vomiting during pregnancy
- Premenstrual Syndrome (PMS)
- For eye health
- Adjust for sleep cycles
- Rheumatoid Arthritis (RA)
- Support for brain function (nootropic)
Pyridoxine has also been tested for asthma, cancer, dysmenorrhea, and cardiac health. Although there have been some promising results from preliminary clinical trials, this study is currently limited.
More clinical trials are needed to determine the therapeutic efficacy of pyridoxine in these and other cases.
FDA Approves Injection of Vitamin B6 and Pyridoxine-Doxylamine (Diclegis) as Prescription Drugs for Morning Sickness.
Vitamin B6 supplements have not been approved by the FDA as a drug for the prevention or treatment of any medical condition. These products are marketed to support body structure and function, but cannot claim to cure any disease.
Vitamin B6 Deficiency
Vitamin B6 deficiency is rare among people who eat healthy and nutritious foods.
Deficiencies may occur in patients with elevated blood levels of urea (uremia), cirrhosis of the liver, malabsorption disorders, alcoholism, in pregnant women, congestive heart failure and/or hyperthyroidism.
Deficiency is also more likely to occur with certain types of prescription drugs.
A comprehensive database of ‘natural medicines’ shows that pyridoxine deficiency in adults mainly affects the mucous membranes, peripheral nerves, skin and hematopoietic system (blood organs). B6 deficiency in children can also affect the CNS.
Some symptoms of B6 deficiency are general seizures, abnormal electroencephalogram readings, weakness, dizziness, inflammation, irritability, confusion, and depression.
Other symptoms include swelling and redness of the tongue and/or sores in the mouth, especially in the corners of the mouth.
Sources of Vitamin B6 in Food
Pyridoxine is found in many food sources in small amounts. Some of the best food sources of pyridoxine are:
Wheat Germ, Bananas, Sunflower Seeds, Lentils, Beans, Legumes, Brown Rice, Liver, Salmon, Shrimp, Tuna, Turkey, Chicken, Milk, Cheese.
Green leafy vegetables such as spinach, pumpkin, cabbage, and dandelion greens also provide adequate levels of pyridoxine. Some fortified cereals and other cereal products also contain this important nutrient.
If possible, choose organic sources. If you’re eating meat, consider choosing grass-fed organic meats that are free of antibiotics, steroids, and growth hormones.
It is recommended to get nutrients such as pyridoxine from food sources where possible.
This is not possible for some people with certain medical conditions or life circumstances. In these cases, taking supplements can be helpful.
Vitamin B6 Supplements, Their Intake, And Dosage
University of Michigan Medical Center says vitamin B6 supplements are available in capsules, tablets, chewing gum, liquid drops, and lozenges.
The most common formulations of pyridoxine are 25 mg, 50 mg, and 100 mg.
According to the NMCD, there are over 19,000 commercially available dietary supplements containing B6, alone or in combination.
It is commonly labeled as pyridoxal, pyridoxamine, pyridoxine hydrochloride and pyridoxal-5-phosphate.
Let’s recap the recommended daily dose is 100 mg daily. Higher doses should be discussed with your doctor.
When taken with food, the dosage ranges from 25 to 100 mg per day.
The following doses were studied in the studies:
- Anemia: 25 mg/day in combination with other vitamins
- Cardiovascular Disease: 40 mg daily
- Cognitive function: 20 mg daily for 12 weeks
- Dysmenorrhea: 200 mg daily
- PMS: up to 600 mg daily; the recommended optimal dose is 100 mg/day
UMM states that although higher doses of vitamin B6 have been studied, doses above 100 mg daily should not be used without the advice and supervision of a physician.
Excessive doses of pyridoxine can cause nerve dysfunction or disease (neuropathy).
Pyridoxine Side Effects
The NMCD evaluates vitamin B6 as likely to be safe for healthy adults if properly administered orally, parenterally, or by injection. Vitamin B6 injection is a prescription drug that can only be prescribed by a doctor.
NMCD says pyridoxine is expected to be safe when taken orally by pregnant or breastfeeding women. However, it is recommended that it should not be used for long periods or without medical advice and dosage recommendations.
Vitamin B6, when taken in the right doses, is well tolerated by many people. While side effects are unlikely, some of the side effects are loss of appetite, drowsiness, abdominal pain, vomiting, allergic reaction, nausea, paraesthesia (tingling or numbness usually seen in the extremities).
Breast sensitivity (mastalgia), breast enlargement, photosensitivity, certain skin disorders and decreased levels of folate in the blood are also possible.
More serious side effects, such as neuropathy, are also possible but are unlikely when taken with normal amounts of this vitamin. These dangerous results are usually associated with high doses over time.
Pyridoxine Interaction with Medicines
Vitamin B6 may interact with certain prescription drugs and its uptake may be significantly affected by other drugs and some herbal supplements.
Consult your doctor before using vitamin B6 supplements with antibiotics such as cycloserine, antiepileptic drugs such as Valproic acid, antihypertensive drugs such as captopril, and anti-asthmatics such as theophylline.
The NMCD recommended caution when taking vitamin B6 supplements with herbs that lower blood pressure, including Andrograph, Casein peptides, Coenzyme Q10, Fish oil, L-arginine, Stinging nettle, L-Theanine.
Other interactions are possible. If you are interested in vitamin B6 supplementation, talk to your doctor to determine if this product is right 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.