“Vitamin B6 is involved in the metabolism of amino acids and the synthesis of neurotransmitters”, summarizes ANSES. It is present in many plants (cereals, starchy vegetables, legumes, products derived from soya, non-citrus fruit, etc.) and in animal products (beef, veal, pork and poultry liver, fish), deficiencies are therefore rare.
The recommended intakes for adults are 1.8 mg/day for men, 1.5 mg/day for women. They are higher in pregnant and breastfeeding women (2mg/day) and in the elderly (2.2 mg/day), and lower in children and adolescents.
A risk of overdose
Vitamin B6 deficiencies can occur following taking certain antibiotics, certain hypertensives (hydrazines), mushroom poisoning or even in the event of chronic alcoholism.
Similarly, taking certain anticonvulsants, antiasthmatics or oral contraceptives can significantly lower B6 levels.
A deficiency in this vitamin leads to the appearance of anemia, convulsions, skin symptoms (eczema, seborrheic dermatitis, etc.) and neurological symptoms (tingling in the hands and feet). Supplementation with B6 (in the form of pyridoxine) is then necessary.
Nevertheless, apart from these proven deficiencies, taking pyridoxine exposes you to a risk of hypervitaminosis, with deleterious effects. Excess can indeed induce neuropathies. The exposure threshold associated with this toxicity is not known (because it depends on the dose, the duration of exposure and the terrain specific to each person, etc.), but a maximum limit of 25 mg/day in adult was fixed.
