Vitamin B6

What is it?

Discovered in 1935, vitamin B6 was synthesized in a laboratory in 1939. Its various functions were discovered by scientists in the following years.

Although it is not synthesized by the body, vitamin B6, also known as pyridoxine, is an essential component for the body’s functioning. This water-soluble vitamin, which belongs to the B group, breaks down into six active forms.

These include: pyridoxine, pyridoxamine, pyridoxine 5-phosphate, pyridoxamine 5-phosphate, pyridoxal, and pyridoxal-5-phosphate or PLP. It is in this latter form that vitamin B6 compounds are transformed after digestion and assimilation.

To be properly absorbed, vitamin B6 requires the presence of all other vitamins of the group in adequate and sufficient quantities.

The body cannot store vitamin B6 in any of its forms. Its intake is therefore primarily dietary. Fruits and vegetables provide vitamin B6 intake in the form of pyridoxine, while animal products provide the following forms: pyridoxamine 5-phosphate and pyridoxal 5-phosphate.

This information is essential to adapt dietary intake and ensure sufficient supply of this nutrient.

Role and benefits of vitamin B6

Vitamin B6 plays several essential functions in the body. The roles of vitamin B6 are:

• Participates in the absorption of vitamin B12, magnesium, and the synthesis of hydrochloric acid.
• Involved in amino acid metabolism, thus in protein production.
• Acts as a precursor for the synthesis of hemoglobins, red blood cells, immune cells (antibodies), and neurotransmitters (serotonin, dopamine, noradrenaline). As such, vitamin B6 contributes to the balance of the immune system, as well as to maintaining the individual’s psychological and nervous balance.
• Ensures the conversion of tryptophan into vitamin B3.
• Also involved in producing the energy needed by the body, from carbohydrate compounds stored in the muscles (glycogen).

The therapeutic virtues attributed to vitamin B6 are:

• Reduction of premenstrual symptoms (irritability, anxiety, abdominal pain, and bloating).
• Reduction of nausea and vomiting, especially during the first trimester of pregnancy.
• Prevention of cardiovascular diseases (in association with the intake of vitamins B9 and B12).

There are dietary supplements enriched with vitamin B6 available for purchase. However, it is advisable to consult a doctor before taking any medication or vitamin B6 supplementation.

Symptoms of vitamin B6 deficiency

Vitamin B6 deficiencies impact amino acids, protein metabolism, and the different functions mentioned earlier.

Vitamin B6 deficiencies are generally observed in people who are malnourished or suffering from kidney failure.

Alcoholism, hyperthyroidism, and rheumatoid arthritis can also cause vitamin B6 deficiencies. The characteristic symptoms of deficiencies are:

• Megaloblastic anemia: this condition affects the stem cells, precursors of red blood cells
• Irritability
• State of confusion
• In alcoholics: glossitis, or inflammation of the tongue
• Fatigue
• Muscle loss
• Depression
• Skin cell alteration
• Peripheral neuropathy: this condition causes pain in the extremities (hands, feet…), difficulty walking

Recommended nutritional intake

The recommended daily intake of vitamin B6 is easily met through diet. As with any nutrient, it varies depending on age, growth phase, and the individual’s sex.

• Infants from 0 to 1 year: 0.3 mg/day
• Child aged 1 to 3 years: 0.5 to 0.6 mg/day  
• Child aged 4 to 8 years:   0.6 to 0.8 mg/day
• Child aged 9 to 13 years: 1 to 1.3 mg/day
• Adolescent aged 13 to 15 years: 1.2 to 1.5 mg/day
• From 16 years old: 1.5 to 1.8 mg/day
• Pregnant or breastfeeding women: 2 mg/day
• Seniors (> 75 years): 2.2 mg/day

Top 5 foods containing vitamin B6

Vitamin B6 is present in most foods, making its absorption easy within a balanced diet.

Many breakfast cereals, available in supermarkets, are enriched with vitamin B6. However, they are very high in sugar, so should be consumed in moderation. Here are our five favorite foods containing vitamin B6.

1. Fatty fish

Rich in healthy fatty acids, fatty fish like mackerel, salmon, or tuna contain vitamin B6. The vitamin content ranges from 0.5 to 0.7 mg per 100 g of fish.

To be consumed at least twice a week, these fish are delicious grilled, steamed, or en papillote. They are the foundation of balanced meals when paired with vegetables or carbohydrates. A simple squeeze of lemon can enhance the taste of your fish dishes without added fat.

2. Offal

Rich in iron and vitamin B9, offal such as calf, lamb, chicken, or veal liver also contains vitamin B6.

With a content reaching 0.7 to 1.2 mg per 100 g, adding this food to your menu helps ensure your recommended daily vitamin B6 intake, depending on your age.

Cook grilled, in a pan, or in the oven for a dish that is both flavorful and light. If you are pregnant, it is advisable to avoid consuming offal.

3. Poultry

Turkey and chicken are low-calorie meats, belonging to the poultry category. They are rich in vitamin B6 (around 0.6 g for 100 g of turkey or chicken breast).

Consuming grilled chicken or turkey breasts in the oven, without the skin, is the foundation of a dietetic and low-fat diet. Consider them for preparing light meals while enjoying the savory taste of these meats.

You can enjoy them with a variety of vegetables, along with an essential portion of carbohydrates, to avoid mid-afternoon or nighttime hunger pangs.

4. Potatoes

Baked potatoes contain 0.3 mg of pyridoxine per 100 g. Great news, there are a thousand ways to cook them!

Potatoes are the base of delicious dishes, like mashed potatoes, crushed potatoes, gratins, or soups. It’s up to you how to consume them. Added to a meal, a portion of mashed or crushed potatoes provides a good carbohydrate intake.

5. Pistachios

Pistachios are generally consumed roasted as an aperitif. In this form, they provide about 1.4 g per 100 g.

However, they remain very high in calories. It is better to consume them in small quantities to benefit from their vitamin B6 advantages. An alternative is to incorporate them into dishes and salads!

Good to know: Wheat germ and brewer’s yeast are supplements rich in vitamin B6. Content: 1.4 mg per 100 g for the former and 2.6 mg per 100 g for the latter.

A final reminder: vitamin B6 is a water-soluble vitamin. To minimize its loss during cooking, opt for steaming, baking, or en papillote methods.

Hazards, Adverse Effects, and Overdose in Vitamin B6

In high doses, vitamin B6 is neurotoxic, meaning it alters brain cells, notably those of the nervous system. Adverse effects observed in these circumstances include:

• Memory disorders
• Neurological disturbances, even neuropathy

To avoid the occurrence of these ailments, specialists have established a daily dosage not to exceed. It corresponds to 5 mg in addition to the recommended daily intake for a given age group. For a 13-year-old child, for example, it should be between 6.2 mg and 6.5 mg/day.

To limit vitamin B6 overdoses, it is better to refrain from consuming pyridoxine-enriched dietary supplements. If deficiency is suspected, the reflex should be to consult a doctor to prevent the onset of potential complications.

Overdose symptoms typically disappear a few months after stopping supplementation.