John Myers
Vitamin B6 affects metabolism, hormones and nerves. But a shortage is very rare.
The essentials in brief:
- Vitamin B6 is an important reaction partner in many metabolic processes.
- With a normal mixed diet, sufficient vitamin B6 is ingested.
- A deficiency can lead to severe nervous disorders, but occurs almost exclusively with malnutrition.
- High-dose vitamin B6 products for athletes, mostly from the Internet, can be harmful to health if taken long-term.
What is behind the advertising for vitamin B6?
“Provides peace and balance” and “participates in the production of neurotransmitters such as serotonin” promise the manufacturers and warn “a deficiency leads to mood swings, difficulty concentrating, insomnia and irritability”.
Vitamin B6 is often advertised together with other B vitamins. e.g. as “brain vitamins”, “happiness vitamins” or “anti-stress vitamins”. Target groups for advertising are often menopausal women or athletes .
Some health promises, so-called health claims , are approved for vitamin B6 . Among other things, it may be advertised that B6 “contributes to normal mental function”, “to normal function of the nervous system”, “to reduce fatigue and tiredness” or “to regulate hormone activity”.
Together with vitamins B12 and folate, vitamin B6 plays an important role in homocysteine metabolism. Homocysteine is a metabolic product which, in higher quantities, disrupts the metabolism of neurotransmitters, among other things. The health claim “contributes to a normal homocysteine metabolism” is therefore approved for vitamin B6, as for the other two vitamins mentioned.
It is unclear whether vitamin B6 has a preventive effect on cardiovascular, skin and nerve diseases.
The vitamin is found in different forms in the body. Of particular importance is the form PLP (pyridoxal-5′-phosphate), which acts as a coenzyme in about 100 enzymatic reactions, e.g. in amino acid metabolism is involved. The statement by suppliers that products with PLP can be used directly by the organism and no longer have to be converted in the body is not correct: During the digestive process, there is a breakdown first. In the liver, blood and kidneys, there is a constant conversion of the various precursors and forms of the vitamin. This produces, among other things, PLP, which is stored in the muscles.
What should I watch out for when taking vitamin B6 products?
It is hardly possible that you take in too much vitamin B6 through food. In dietary supplements, however, B6, like other vitamins, is often used in high doses. The Federal Institute for Risk Assessment (BfR) recommends that adults and young people over the age of 15 take no more than 3.5 mg of vitamin B6 per day from food supplements. Total intake amounts of more than 25 mg per day are not considered safe, in adolescents it should be a maximum of 5 to 20 mg, depending on body weight. In its 2019 test of multivitamin preparations, the magazine Öko-Test found increased dosages for some products , including vitamin B6.
Especially vitamin B6 products for athletes from the Internet sometimes provide more than 3,000% of the daily requirement or the intake recommendations, as the Bavarian State Office for Health and Food Safety determined in 2015. You can recognize these very high dosages by the fact that the nutrient reference value (NRV or nutrient reference value) given on the packaging in the nutritional value table for the daily intake is significantly higher than 100% (e.g. “3,500% NRV”).
Large amounts of vitamin B6 do not appear to be acutely toxic. However, long-term intake of large amounts can lead to nerve disorders or neuropathies. The following have been observed: problems with walking due to muscle weakness, a special sensitivity to sunlight, skin rashes, unpleasant tingling in hands or feet, unsteady walking, painful paraesthesia or numbness.
According to an American study from 2017 with 77,000 participants, male participants who took high-dose vitamin B6 (over 20 mg per day) and vitamin B12 (over 55 µg per day) for several years had a significantly increased risk of lung cancer. Smokers were particularly badly affected.
Since two Norwegian intervention studies surprisingly showed an increase in hip fractures in menopausal women after taking vitamin B6, data from the Nurses’ Health Study was evaluated. In this cohort study, a combined high intake of vitamins B6 and B12 was associated with an increased risk of hip fracture. Ultimately, an observational study cannot prove that taking the two vitamins was actually responsible for the increased risk of fractures and, if so, how this happens. However, since there is no scientifically proven benefit from taking the vitamins, the scientists believe that healthy people should avoid taking them as a precaution.
Very high doses of vitamin B6 can impair the effects of medication , e.g. the effect of levodopa (medicine for Parkinson’s disease) is reduced.
In breastfeeding women, high doses of vitamin B6 can inhibit milk production.
A notice:
These vitamin B6 compounds are approved for use in food supplements in Germany and other EU countries (according to EU Directive 2002/46/EG, Annex II (version of 03/10/2021)):
- Pyridoxinhydrochlorid
- Pyridoxin-5′-phosphat
- Pyridoxal-5′-phosphat
What does the body need vitamin B6 for?
Vitamin B6 is a collective term for various related substances such as pyridoxine, pyridoxamine and pyridoxal. They regulate central processes in the body. Vitamin B6 is the most important coenzyme in the amino acid metabolism. Together with folate and other B vitamins, it regulates homocysteine metabolism. It is involved in the formation of messenger substances in the nerves and in fat metabolism. The vitamin influences certain hormone activities and has an impact on the immune system.
Vitamin B6 is one of the water-soluble vitamins. With an adequate supply, around 100 mg are stored in the muscles in the body, excess amounts are excreted via the kidneys with the urine.
A lack of this vitamin is very rare in healthy people, since enough of it is usually ingested with food. This also applies to athletes. Chronic indigestion, alcohol dependence or not eating enough, e.g. through frequent dieting or in older people, but can lead to deficiency symptoms. These are e.g. anemia, rashes and sores on the mouth, diarrhea, vomiting and cramps.
Can I cover my daily requirement through food?
Women can easily cover their vitamin B6 requirement of 1.4 mg per day and men of 1.6 mg with a varied diet. Pregnant women (1.5 or 1.8 mg/day) and breastfeeding women (1.6 mg/day) have an increased need, but hardly any problems in reaching these values. Only seniors in nursing homes represent a risk group.
Vitamin B6 is widely found in plant and animal foods. However, the availability from animal foods is significantly higher than from plant foods, especially if their fiber content is high.
You can find particularly good animal sources in fish, such as salmon or mackerel, meat and liver. Dairy products tend to contain smaller amounts. However, if you consume them in large quantities, they are also good sources of vitamin B6.
When it comes to plant-based foods, you can use nuts, whole grains, potatoes, vegetables such as tomatoes, red peppers and carrots, and legumes.
Tip: For grain products, preferably choose the whole grain variety. Vegetables should be cooked gently and with little water. Ensure that vegetables and potatoes are stored away from the sun and light.
Facebook Comments