Vitamin B 6 deficiency

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Classification according to ICD-10
E53.1 Pyridoxine deficiency
ICD-10 online (WHO version 2019)
Pyridoxine

Vitamin B 6 deficiency (also known as pyridoxine deficiency ) is a deficiency in pyridoxine , pyridoxamine , pyridoxal and the phosphorylated derivatives of these chemical compounds. A deficiency in vitamin B 6 is very rare and occurs in connection with malnutrition and the use of certain medications. The main symptoms are dermatitis , glossitis, and microcytic anemia .

root cause

About reduced levels of pyridoxal-5-phosphate (PLP), which is the main active form of vitamin B 6 , in the blood plasma was with asthma , diabetes mellitus , alcoholism , heart disease , pregnancy , breast cancer , Hodgkin's lymphoma and sickle cell anemia reported. Patients with uremia can also be affected. Since vitamin B 6 is abundant in some foods, but is also sensitive to light and heat, an unbalanced diet or malnutrition are other possible causes.

The drugs isoniazid , penicillamine , hydralazine and levodopa / carbidopa are associated with vitamin B 6 deficiency, as they interfere with the pyridoxine metabolism.

Few cases occurred between 1952 and 1953, mostly in the United States, in children who received breast milk substitutes without pyridoxine.

Clinical appearance

A slight deficiency in vitamin B 6 causes unspecific symptoms such as stomatitis , glossitis , cheilitis , confusion , depression and possibly peripheral neuropathy . Severe deficiency is associated with seborrheic dermatitis , microcytic anemia, and seizures .

Vitamin B 6 deficiency can lead to increased plasma homocysteine ​​concentrations , which is a risk factor for atherosclerosis and venous thrombosis .

Pyridoxine-dependent epilepsy

An innate defect in pyridoxine metabolism is responsible for pyridoxine-dependent epilepsy, which leads to difficult-to-treat seizures in newborns.

Investigation methods

Examinations of the vitamin B6 status are traditionally divided into direct tests (vitamin concentrations in the blood plasma, blood cells or urine ) or indirect tests ( aminotransferase saturation of erythrocytes by pyridoxal-5'-phosphate [PLP] or tryptophan metabolites ). These tests usually show the relative level of vitamin B 6 intake. They are only suitable for determining a vitamin B 6 increase or decrease in the body. Absolute values ​​that indicate sufficient supply or a shortage are generally problematic to record. There is therefore little scientific evidence as to which test results indicate a sufficient level or an actual deficiency.

Pyridoxal-5'-phosphate (PLP) in blood plasma is probably the best single indicator of the body's vitamin B 6 status, as it reflects the degree of tissue deposition.

Plasma PLP is measured using an enzymatic test called the apo-tyrosine decarboxylase assay. This assay is well standardized and there is usually good agreement between laboratories.

treatment

When treating vitamin B 6 deficiency, the missing vitamin is replaced. Since overdosing can cause permanent neurological damage, different maximum daily doses are recommended. While 100 mg per day is a safe limit, doses between 200 mg and 500 mg per day or 15 to 30 mg per kg of body weight and day are used in the therapy of acute seizures in the case of pyridoxine-dependent epilepsy. Alternatively, therapy with pyridoxal phosphate is also possible.

Ingestion with food

The recommended daily dietary dose of vitamin B6 for healthy people ranges from 0.5 to 1 mg in children, 1.3 mg in young women and men and increases to 1.7 mg and 1.5 mg for men over 50 years of age for women older than 50 years.

Individual evidence

  1. ↑ James E. Leklem: Handbook of Vitamins - Vitamin B6 . Ed .: Lawrence J. Machlin. 2nd Edition. M. Dekker, 1991, ISBN 978-0-8247-8351-8 , ISSN  0071-7223 .
  2. ↑ Shyamala Dakshinamurti, Krishnamurti Dakshinamurti: Handbook of Vitamins . Ed .: Robert B. Rucker, Janos Zempleni, John W. Suttie, Donald B. McCormick. 4th edition. CRC Press, 2012, ISBN 978-1-4200-0580-6 , Vitamin B6, pp. 321 .
  3. ↑ a b Amer A. Ghavanini, Kurt Kimpinski: Revisiting the evidence for neuropathy caused by pyridoxine deficiency and excess . In: Journal of clinical neuromuscular disease . tape 16 , no. 1 , September 2014, p. 25-31 , doi : 10.1097 / CND.0000000000000049 (English, review).
  4. ^ Philippe Lheureux, Andrea Penaloza, Mireille Gris: Pyridoxine in clinical toxicology: a review . In: European journal of emergency medicine . tape 12 , no. 2 , April 2005, p. 78-85 , doi : 10.1097 / 00063110-200504000-00007 (English).
  5. ^ A b Andrews' Diseases of the Skin. 10th edition. Saunders Elsevier, 2006, ISBN 0-7216-2921-0 .
  6. ^ A b John H Menkes: Textbook of Child Neurology . Henry Kimpton Publishers, 1980, ISBN 0-8121-0661-X .
  7. ↑ a b c d National Academies Press (Ed.): Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Folate, Other B Vitamins, and Choline. Dietary Reference Intakes for Thiamine, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline - 7, Vitamin B6 . Washington (DC) 1998, ISBN 0-309-59725-0 (English, nih.gov ).
  8. ↑ EB Rimm, WC Willett, FB Hu, L. Sampson, GA Colditz, JE Manson, C. Hennekens, MJ Stampfer: Folate and vitamin B6 from diet and supplements in relation to risk of coronary heart disease among women . In: JAMA . tape 279 , no. 5 , February 4, 1998, pp. 359-364 , doi : 10.1001 / jama.279.5.359 (English).
  9. ↑ A. Lui, L. Lumeng, GR Aronoff, TK Li: Relationship between body store of vitamin B6 and plasma pyridoxal-P clearance: metabolic balance studies in humans . In: The Journal of laboratory and clinical medicine . tape 106 , no. 5 November 1985, pp. 491-497 , PMID 4056565 (English).
  10. ↑ How much vitamin B6 is toxic? dated November 12, 2005
  11. ↑ Pyridoxine dependent epilepsy and antiquitin deficiency: clinical and molecular characteristics and recommendations for diagnosis, treatment and follow-up from May 24, 2011
  12. ↑ Institute of Medicine (Ed.): Dietary Reference Intakes - The Essential Guide to Nutrient Requirements . The National Academies Press, Washington DC 2006, ISBN 978-0-309-15742-1 , doi : 10.17226 / 11537 .