Vitamin B6 (synonym: pyridoxine) is a vital dietary component of the vitamin B complex. If it is not supplied to the body, deficiency symptoms (hypo-/avitaminosis) will result. Three forms of pyridoxine can be distinguished: Pyridoxal, Pyridoxamine and Pyridoxol. Vitamin B6 is water-soluble and photosensitive. It cannot be stored and absorption beyond the requirement is not possible. Vitamin B6 is absorbed in the human body in the small intestine. It is found mainly in green vegetables, cereals, rice, eggs, meat, nuts and yeast. The main role of vitamin B6 is as a coenzyme in many different metabolic processes such as amino acid cleavage. Amino acids are the components of proteins (egg white). Furthermore, vitamin B6 is involved in the synthesis of serotonin, nicotinamide and tryptophan. The following symptoms may occur with a vitamin B6 deficiency:
- Anemia, iron refractory, hypochromic microcytic (anemia).
- Anorexia nervosa (anorexia nervosa)
- Depression
- Diarrhea (diarrhea)
- Inflammation of the mouth
- Increased excitability
- Limer’s disease (increased excitability, jumpiness, seizures – occurs in infants fed highly heated formula milk)
- Paresthesias (sensory disturbances)
- Pigmentation disorders
- Sleep disorders such as insomnia
- Seborrheic dermatitis (skin inflammation) in the nose and eye area associated with increased sebum production
- Nausea / vomiting
Pregnant women with a vitamin B6 deficiency may experience disorders such as eclampsia. This is a condition that can lead to headaches, edema (water retention in the tissues) and seizures.
The procedure
Material needed
- EDTA blood
Preparation of the patient
- Not necessary
Disruptive factors
- The following drugs can distort the measured values.
- Antidepressants – medications used to treat depression.
- Antiepileptic drugs – drugs used for epilepsy.
- Oral contraceptives (“pill”).
Standard values
| Value in μg/l | |
| Normal range | 8,7-27,2 |
Indications
- Suspected vitamin B6 deficiency
- Long-term therapy with isoniazid – tuberculostatic drug; drug against tuberculosis (consumption).
Interpretation
Interpretation of increased values
- Only possible by intravenous administration (from 1,000-2,000 mg/d) → may lead to neuritis (nerve inflammation)
Interpretation of lowered values
- Alimentary (nutritional)
- Malnutrition or nutritional deficiency
- Chronic alcohol abuse
- Tobacco use
- Malabsorption (disorder of absorption)
- Chronic inflammatory bowel disease such as Crohn’s disease or ulcerative colitis.
- Celiac disease (gluten-induced enteropathy; chronic disease of the small intestinal mucosa (lining of the small intestine) based on hypersensitivity to the grain protein gluten)
- Diseases
- Renal diseases – chronic dialysis, chronic uremia, renal insufficiency.
- Medication
- Women who are taking oral contraceptives (“the pill”)
- Long-term use of isoniazid – tuberculostat; drug against tuberculosis (consumption).
- Hydralazine, certain hydrazide-containing tuberculostatic drugs, phenytoin, D-penicillamine, L-dopa.
- Other causes
- Genetic pyridoxine metabolic defect.
- Increased need
- BMI (body mass index) – < 18.5, which means underweight.
- Pregnant women / breastfeeding
- Age ≥ 65 years
Further notes
- Pyridoxine can be used as a medication in women suffering from premenstrual syndrome (PMS).
- The normal requirement of vitamin B6 is 1.4 mg/d in women and 1.6 mg/d in men.
Attention. Note on the state of supply (National Consumption Study II 2008) 17.5% of men and 25% of women aged 35 years and older do not reach the recommended daily intake (for more see “National Consumption Study (nutrition situation)”.
