Vitamin B6 – Functions, Deficiency and Daily Needs
Vitamin B6 is a water-soluble vitamin essential for metabolism, nervous system function, and red blood cell production. It plays a key role in over 100 enzymatic reactions in the body.
Wissenswertes über "Vitamin B6"
Vitamin B6 is a water-soluble vitamin essential for metabolism, nervous system function, and red blood cell production. It plays a key role in over 100 enzymatic reactions in the body.
What is Vitamin B6?
Vitamin B6 is a water-soluble vitamin belonging to the B-vitamin family. It occurs naturally in three forms: pyridoxine, pyridoxal, and pyridoxamine. In the body, all three forms are converted into the biologically active form pyridoxal-5-phosphate (PLP), which acts as a coenzyme in more than 100 enzymatic reactions.
Biological Functions
Vitamin B6 plays a wide range of vital roles in the human body:
- Protein metabolism: Vitamin B6 is essential for the breakdown and conversion of amino acids.
- Nervous system: It is involved in the synthesis of key neurotransmitters such as serotonin, dopamine, and GABA.
- Blood formation: Vitamin B6 supports the production of hemoglobin, the protein in red blood cells that carries oxygen.
- Immune function: It promotes the production of antibodies and supports immune defense.
- Hormone regulation: It influences the activity of steroid hormones.
- Homocysteine metabolism: Together with vitamin B12 and folate, vitamin B6 helps regulate homocysteine levels in the blood, potentially reducing cardiovascular risk.
Dietary Sources
Vitamin B6 is found in a wide variety of foods. Particularly rich sources include:
- Meat and poultry (e.g., chicken breast, beef)
- Fish (e.g., salmon, tuna)
- Legumes (e.g., chickpeas, lentils)
- Nuts and seeds (e.g., sunflower seeds, walnuts)
- Whole grains
- Potatoes and starchy vegetables
- Bananas
Recommended Daily Intake
The World Health Organization (WHO) and other health authorities provide the following daily intake recommendations for vitamin B6:
- Adult men (19–50 years): approximately 1.3–1.7 mg/day
- Adult women (19–50 years): approximately 1.3–1.5 mg/day
- Pregnant women: approximately 1.9 mg/day
- Breastfeeding women: approximately 2.0 mg/day
- Older adults (65+ years): up to 1.7–1.8 mg/day
Deficiency Symptoms
Vitamin B6 deficiency is uncommon in Western populations but can occur in certain at-risk groups. Common symptoms include:
- Skin changes such as seborrheic dermatitis (scaly, oily skin inflammation)
- Inflammation of the mouth and lips (cheilitis, glossitis)
- Irritability, confusion, and depression
- Peripheral neuropathy (numbness and tingling in hands and feet)
- Anemia (low red blood cell count)
- Weakened immune system
Groups at Risk of Vitamin B6 Deficiency
- People with kidney disease
- Individuals with autoimmune conditions (e.g., rheumatoid arthritis)
- People with alcohol dependency
- Those taking certain medications (e.g., isoniazid for tuberculosis treatment)
- Older adults
Overdose and Toxicity
As a water-soluble vitamin, excess vitamin B6 is generally excreted through urine. However, very high supplemental doses (above 100 mg per day over extended periods) can cause sensory neuropathy -- a form of nerve damage characterized by numbness and coordination problems. The European Food Safety Authority (EFSA) recommends a tolerable upper intake level of 25 mg/day for adults from supplements.
Interactions with Other Nutrients and Medications
- Vitamin B12 and folate: Together they regulate homocysteine metabolism.
- Magnesium: Supports the conversion of pyridoxine into its active form.
- Isoniazid and penicillamine: These medications can interfere with vitamin B6 metabolism and lead to deficiency.
- Levodopa (L-Dopa): High doses of vitamin B6 may affect the efficacy of levodopa used in Parkinson's disease treatment.
References
- World Health Organization (WHO) – Vitamin and Mineral Requirements in Human Nutrition, 2nd Edition (2004).
- National Institutes of Health (NIH), Office of Dietary Supplements – Vitamin B6 Fact Sheet for Health Professionals (2023). Available at: ods.od.nih.gov
- Stach K, Stach W, Augoff K – Vitamin B6 in Health and Disease. Nutrients. 2021;13(9):3229. PubMed PMID: 34579105.
Best-selling products
For your universal protection
As one of the most valuable proteins in the body, lactoferrin is a natural component of the immune system.
For your iron balance
Specially formulated for your iron balance with plant-based curry leaf iron, Lactoferrin CLN®, and natural Vitamin C from rose hips.
For Healthy Oral Flora & Dental Care
Formulated lozenges with Dentalac®, probiotic lactic acid bacteria, and Lactoferrin CLN®The latest entries
3 Posts in this encyclopedia categoryRib Contusion
Cartilage Damage
Most read entries
3 Posts in this encyclopedia categoryMagnesiumcarbonat
Cologne list
Calorie content
Related search terms: Vitamin B6 + Vitamin B 6 + Pyridoxine + Pyridoxal + Pyridoxamine