Vitamin B6

Vitamin B6 is a natural supplement belonging to the supplement category of the water-soluble vitamins class.

Vitamin B6 is also known as pyridoxine.

A deficiency of Vitamin B6 may lead to various health issues and symptoms like neurological problems, anaemia, skin problems, cognitive impairment with advancing age, metabolism impairment and a weak immune system.

Vitamin B6 is mainly absorbed in the proximal part of the small intestine through active transport. The liver, muscles, and brain tissues are the primary organs where vitamin B6 is distributed and metabolized. Excretion of excess vitamin B6 is through urine via the metabolic process of converting to its active coenzyme forms, such as pyridoxal phosphate.

Half-life: 15-20 days

The common side effects of vitamin B6 include abdominal pain or discomfort, nausea, headache and loss of appetite.

Vitamin B6 is available in various forms, like tablets and capsules.

Whole grains, beans, lentils, green peas, sunflower seeds, avocado, mushrooms, nutritional yeast, peanuts, muesli and asparagus are natural plant sources of Vitamin B6. The primary sources of Vitamin B6 in animals are meat, poultry, and fish.

Biochemical action of vitamin B6

Vitamin B6 belonging to the water-soluble vitamins, is vital for maintaining overall health.

An active form of vitamin B6 known as pyridoxal-5'-phosphate (PLP) is a versatile coenzyme that can catalyze various processes, including transamination, decarboxylation, racemization, and elimination. By weakening the bonds surrounding the alpha-carbon atom in amino acids, both when coupled to enzymes or in its free form, PLP's electron-withdrawing properties promote these processes. The effective functioning of several metabolic pathways and the support of various physiological processes in the body are all facilitated and accelerated by this electron transport process.

Vitamin B6 is available in the form of tablets and capsules.

Tablets and capsules will be swallowed whole with water/liquid, as applicable.

Supplemental vitamin B6 is useful for supporting specific physiological metabolic processes.

• Vitamin B6 supplement supports maintaining an immune system that is powerful by encouraging the production of antibodies and white blood cells.
• Vitamin B6 supplement produces serotonin, dopamine, and norepinephrine neurotransmitters, which are crucial for mood control and cognitive function.
• Vitamin B6 is helpful for athletes and physically active people as it supports protein synthesis and muscle recovery after exercise.

Vitamins and natural supplements should not replace a balanced diet

This product is not intended to diagnose, treat or prevent any disease(s).

Vitamin B6 may be useful as a supplement for the following health benefits:

• Treatment of vitamin B6 deficiency: Deficits built on by inadequate dietary intake or specific medical disorders are treated with vitamin B6 supplementation.
• Pregnancy-related nausea: Vitamin B6 supplements have been shown to reduce nausea and vomiting during pregnancy, particularly during the first trimester.
• Neurological conditions: Vitamin B6 supplement is an adjunctive therapy for managing conditions like carpal tunnel syndrome, peripheral neuropathy, and epilepsy.
• Dysmenorrhoea: According to some research, taking vitamin B6 pills may assist with PMS symptoms like mood swings and bloating.
• Cardiovascular health: By lowering homocysteine levels associated with an increased risk of heart disease, vitamin B6 may help manage cardiovascular health.
• Immune system support: The immune system's ability to function is facilitated by vitamin B6, which benefits general health.
• Adjuvant in certain medical conditions: Healthcare providers should prescribe and monitor vitamin B6 as an adjuvant therapy, yet only for specific medical problems.
• Cognitive function: Vitamin B6 may play a role in the brain's health, and cognitive performance may be promoted by vitamin B6.
• Enhancing mood: clinical studies showed that vitamin B6 supplements might be beneficial for improving mood and mental well-being.

Vitamin B6 is commonly administered orally before or after meals for all oral solid forms.

The dosage and duration of treatment should be as per the clinical judgment of the treating healthcare professional.

Vitamins and natural supplements should not replace a balanced diet

This product is not intended to diagnose, treat or prevent any disease(s).

• Tablet: 50mg,100mg, 250mg, 500mg
• Tablet extended-release: 500mg, 750mg, 1000mg
• Capsule extended-release: 250mg, 500mg

Vitamin B6 is available in the form of tablets and capsules.

• Limit the consumption of drinks that include caffeine, such as coffee, tea, chocolate, and alcoholic beverages, as this substance could hinder the absorption of Vitamin B6.
• Avoid consuming foods high in fat or cholesterol, or pyridoxine will be less effective.
• Stay within your daily calorie needs.
• Avoid spicy foods.

The dietary restriction should be individualized as per patient requirements.

Recommended Daily Allowance (RDA)

The RDA for adults is 1.3 mg/ day.

Upper Tolerable Intake (UTL):

The UTL set for adults is 100 mg/day.

• Monitor long-term use of high-dose pyridoxine supplements (>100 mg, although this level varies between individuals).
• Hypersensitivity
• Long-term high doses of vitamin B6 are associated with neuropathy.
• Patients with inadequate renal function and newborns must use caution since several parental products include aluminium.
• This may lead to dependence/withdrawal.

The treating healthcare professional must closely keep a watch and monitor for signs and symptoms of adverse reactions like allergies and abdominal cramps. It is advised to discontinue vitamin B6 in case of allergies.

Excessive intake of vitamin B6 can lead to sensory nerve problems, so taking it as per standard RDA is recommended.

Individuals with kidney issues should take vitamin B6 supplements cautiously.

• Vitamin B6 is safe to use during pregnancy but should not take in excess unless recommended by the doctor.

Food may decrease the rate but not the extent of absorption. Limit foods and drinks higher in added sugars, spicy foods, saturated fat, and sodium.

Vitamin B6 supplementation is reported to be well-tolerated and safe to use.

The adverse reactions related to Vitamin B6 can be categorized as-

• Common: Nausea, vomiting, abdominal pain and diarrhoea.
• Less Common: Photosensitivity, skin rashes or itching.
• Rare: Peripheral neuropathy, ataxia, sensory neuropathy and anaphylaxis.

• Amiodarone: Drug-induced photosensitivity may become more frequent if pyridoxine is used. With patients taking pyridoxine and amiodarone together, consider caution.
• Antibiotics: Endogenous synthesis of vitamin B6 can be reduced by the destruction of gut flora. Consider increasing your consumption of foods high in vitamin B6 or consuming supplements.
• Hydralazine: According to a clinical investigation, hydralazine may cause B6 deficiency. In the case of long-term medication therapy, increased consumption may be required.
• Isoniazid: The requirement for vitamin B6 is increased with isoniazid. Increase your consumption of foods high in vitamin B6, or think about taking supplements or receiving long-term medication therapy.
• L-dopa (without carbidopa): The level of hyperhomo- cysteinaemia that l-dopa may cause in people with Parkinson's disease depends on their B vitamin status. B vitamin needs are higher in l-dopa-treated individuals than in patients who do not receive l-dopa medication to maintain appropriate plasma homocysteine concentrations. Supplemental B vitamins may be necessary for PD patients receiving l-dopa treatment.
• Oral contraceptives: Vitamin B6 requirements are increased by oral contraceptives. Increase your consumption of foods high in vitamin B6, or think about taking supplements or long-term medication.
• Penicillamine: The requirement for vitamin B6 is raised by this medication. Increase consumption of foods high in vitamin B6 or think about taking supplements.
• Phenobarbitone, phenytoin: Supplement vitamin B6 may reduce several medications' plasma levels and effectiveness. When taking these medications, watch for drug efficacy and continue cautiously.
• Theophylline: Theophylline causes a deficiency of pyridoxine. With long-term medication therapy, increased consumption may be recommended.

The common side effects associated with Vitamin B6 include:

• Abdominal pain or discomfort

• Nausea

• Headache

• Sensory neuropathy, which causes tingling or numbness in the extremities

• Photosensitivity (increased sensitivity to sunlight)

• Loss of appetite

• Fatigue or drowsiness

• Dizziness

• Irritability or nervousness

These side effects are usually mild and occur only at higher doses of vitamin B6 supplementation. Taking vitamin B6 within the recommended daily intake limits is generally safe for most individuals.

• Pregnancy: Vitamin B6 is essential for various metabolic processes and plays a role in fetal development. It is commonly included in prenatal multivitamin supplements.

The recommended daily intake of Vitamins is 1.9 mg/day.

Pregnancy Category: A/C-when exceeding RDA recommendations.

Safe during pregnancy, but when taken in high doses, use caution if the benefits outweigh the risks.

There is no sufficient scientific evidence regarding the use and safety of Vitamin B6 for special populations.

• Paediatrics:

Vitamin B6 deficiency is higher in children, especially babies; it plays a critical role in promoting brain growth, sustaining cell function, and developing and protecting the body's nervous system.

Dosage Adjustment for Paediatric Patients

Nutritional Supplementation

The recommended daily intake of Vitamin B6 ranges from 0.1-1.3 mg/day.

Isoniazid-Induced Seizures/Coma

The dose of pyridoxine is equal to the amount of isoniazid ingested

Administer at a rate of 0.5-1 g/min until seizures stop or maximum initial dose (70 mg/kg) administered; may administer q5-10min PRN to control persistent seizure activity and CNS toxicity

• Geriatrics:

Vitamin B6 is an excellent antioxidant- helping maintain the cells' health and function, thus reducing the risk of age-related diseases, such as heart disease and dementia.

There is no sufficient scientific evidence traceable regarding the use and safety of Vitamin B6 for use in special populations

• Lactating mothers:

Lactating mothers support the production of breast milk and their own nutritional needs.

The recommended daily intake for lactating mothers is 2mg.

There is no sufficient scientific evidence traceable regarding the use and safety of Vitamin B6 for use in special populations.

Dosage Adjustment in Kidney Impairment

Vitamin B6 (pyridoxine) dose may need to be modified for kidney disease or malfunction to avoid potential side effects.

There are no specific dosage adjustments provided.

Dosage Adjustment in Hepatic Impairment

High pyridoxine dosages might worsen liver damage. If you have liver disease, avoid using high doses as the metabolism of vitamin B6 may be altered.

There are no specific dosage adjustments provided.

Dosage Adjustment in Adult Patients

Pyridoxine Deficiency

10-20 mg/day IV/IM for 3 weeks

2.5-10 mg/day PO

Nausea in Pregnancy

10-25 mg PO q8hr

Prevention of Peripheral Neuropathy

Patients treated with isoniazid for Mycobacterium tuberculosis: 25-50 mg/day PO

Seizures (Orphan)

Treatment of pyridoxine-dependent seizures.

Overdosage of Vitamin B6 supplements may show symptoms like nausea, vomiting, sensory neuropathy, photosensitivity, rash, GI disturbances and headache which are self-limiting.

There is no specific treatment that is recommended in the event of an overdose. When an overdose is suspected, more pyridoxine should be terminated immediately. Supportive treatment should also be given, along with addressing any symptoms that persist or worsen. Physical therapy might be added if necessary.

Biochemistry profile of vitamin B6:

Vitamin B6, generally known as pyridoxine, is a water-soluble vitamin essential for several metabolic reactions in the body. More than 100 enzyme-catalyzed processes require vitamin B6 in its active form, pyridoxal-5'-phosphate (PLP). Amino acids, carbohydrates, and lipids are all metabolized by these processes.

PLP acts as a coenzyme in significant reactions, including transamination, which is essential for the synthesis of proteins and the metabolism of nitrogen. Transamination is a process where amino groups are transferred from one amino acid to another. It is also vital for synthesizing neurotransmitters, including serotonin, dopamine, and gamma-aminobutyric acid (GABA), which impact mood regulation and neurological function, are also synthesized from it, and their synthesis is vital.

Furthermore, PLP synthesizes heme, a haemoglobin component that facilitates oxygen transport in red blood cells, and converts tryptophan to niacin (vitamin B3). Also, it affects the immune system, gene expression, and hormone control.

Kinetic profile:

• Absorption: Vitamin B6 is absorbed mainly in the small intestine through active transport pathways. Before entering the bloodstream, the intestinal mucosa transforms the two primary forms of vitamin B6 that are present in the diet, pyridoxal and pyridoxine, through the active coenzyme form pyridoxal-5'-phosphate (PLP)
• Distribution: PLP is circulated to many tissues and organs via the bloodstream. The liver, muscle, brain, and red blood cells have the highest PLP amounts. Other tissues, such as the kidneys and heart, also contain PLP in lesser amounts.
• Metabolism: PLP serves as a coenzyme within the cells for a number of enzyme-catalyzed events involved in amino acid metabolism, neurotransmitter production, and other critical procedures. The conversion of amino acids and non-essential amino acids from intermediates depend on PLP.

• Excretion: The urine is the main organ of excretion for vitamin B6 and its metabolites. The body excretes any excess vitamin B6 that is not required, preventing a buildup of the vitamin in the body. A small quantity of vitamin B6 is removed from the body via faeces.

1. Braun L, Cohen M. October 1, 2014.Herbs and Natural Supplements; 4th Edition Vol-2. Australia. Elsevier.
2. https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/
3. https://www.ncbi.nlm.nih.gov/books/NBK470579/
4. https://www.ncbi.nlm.nih.gov/books/NBK554500/
5. https://ods.od.nih.gov/factsheets/VitaminB6-Consumer/
6. https://reference.medscape.com/drug/vitamin-b6-nestrex-pyridoxine-34442