The EclecticPhysician

The Eclectic Physician
Vitamin and Mineral Information

Vitamin B-6/ Pyridoxine

The information on this page compiled by
Beth Burch N.D.
(click on the keywords)


Vitamin B-6 or pyridoxine plays vital role in many areas of the body. It is required for the proper functioning of many different enzyme reactions important for amino acid synthesis, the metabolism of fatty acids, the synthesis of prostaglandins, the manufacture of all amino acid neurotransmitters including serotonin, dopamine, melatonin, epinephrine and norepinephrine as well as in the conversion of trytophan to vitamin B-3, the transportation of magnesium across cell membranes and the release of glycogen from the liver. It is important for the health and proper functioning of the immune system, the skin and mucous membranes and red blood cells. Deficiency of pyridoxine results in skin problems, cracking of the lips and tongue, anemia, peripheral neuropathy, depression, insomnia, irritability and depressed immune function. Deficiency can result from inadequate diet, in alcoholics and patients with kidney failure. Many substances inactivate vitamin B-6 including hydrazine dyes (especially yellow #5), a lcohol, and medications including isoniazid, hydralazine, dopamine, penicilliamine. Excessive intake of any of these can result in pyridoxine deficiency. Oral contraceptive use increases the need for vitamin B-6. Vitamin B-6 dependency states have been documented and can produce convulsions and mental retardation in infants.

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  • Pyridoxine hydrochloride
  • Pyridoxal-5-phosphate (activated pyridoxine)

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Food Sources

  • Good sources of vitamin B-6 include nutritional yeast, meat, seeds and nuts, whole grains, legumes and bananas.

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  • Recommended Daily Allowance (RDA)
  • Infants- 0.3-0.6 mg
  • Children (ages 1-10)- 1.0-1.4 mg
  • Adults- 1.5-2.0 mg
  • Pregnancy- 2.2 mg
  • Lactation- 2.1 mg

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Optimal Supplementation

  • 10-25 mg daily

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Treatment of Health Conditions

  • 50-500 mg daily. Doses over 150 mg daily should be monitored by a physician.

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Conditions used for

  • Asthma (2, 5)
  • High blood pressure (15)
  • Carpel tunnel syndrome (3, 14)
  • Chinese restaurant syndrome (4)
  • Chronic fatigue syndrome (12)
  • Depression (6)
  • Epilepsy (1)
  • Kidney stones (8)
  • Morning sickness (16)
  • Premenstrual syndrome (7,10)
  • Elevated homocysteine levels (with vitamin B-12 and folic acid) (17)
  • Vitamin B-6 deficiency and dependency

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Side effects

  • Dosages larger than 150 mg daily over prolonged periods can result in nerve damage characterized by numbness and tingling in the extremities and loss of muscle coordination (11)
  • Dosages greater than 100 mg daily can inhibit milk production in lactating women

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  • Hypersensitivity to pyridoxine products
  • Do not take over 100 mg per day in pregnancy or lactation

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Interactions with other nutrients

  • Vitamin B-2 and magnesium are needed to activate pyridoxine.
  • Vitamin B-6 is necessary for transport of magnesium and zinc across cell membranes

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Interactions with medications and herbs

  • Vitamin B-6 is inactivated by hydrazine dyes (especially yellow #5), alcohol, isoniazid, hydralazine, dopamine, penicilliamine.
  • Theophylline decreases vitamin B-6 levels (9)
  • Oral contraceptives increase the requirement for vitamin B-6
  • Effectiveness of L-dopa is reduced by vitamin B-6 (13)
  • Serum levels of phenobarbital or phenytoin are decreased by pyridoxine

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1. Nabbout R et al, Pyridoxine dependent epilepsy: a suggestive electroclinical pattern, Arch Dis Child Fetal Neonatal Ed 1999;81(2):F125-9
2. Collipp PJ et al, Pyridoxine treatment of childhood bronchial asthma, Ann Allergy 1975 Aug;35(2):93-7
3. Keniston RC et al, Vitamin B6, vitamin C, and carpal tunnel syndrome. A cross-sectional study of 441 adults, J Occup Environ Med 1997;39(10):949-59
4. Folkers K et al, The biochemistry of vitamin B6 is basic to the cause of the Chinese restaurant syndrome, Hoppe Seylers Z Physiol Chem 1984;365(3):405-14
5. Reynolds RD et al, Depressed plasma pyridoxal phosphate concentrations in adult asthmatics, Am J Clin Nutr 1985;41(4):684-8
6. Baldewicz T et al, Plasma pyridoxine deficiency is related to increased psychological distress in recently bereaved homosexual men, Psychosom Med 1998;60(3):297-308
7. Doll H et al, Pyridoxine (vitamin B6) and the premenstrual syndrome: a randomized crossover trial, J R Coll Gen Pract 1989;39(326):364-8
8. Curhan GC et al, Intake of vitamins B6 and C and the risk of kidney stones in women, J Am Soc Nephrol 1999;10(4):840-5
9. Martinez de Haas MG et al, Subnormal vitamin B6 levels in theophylline users, Ned Tijdschr Geneeskd 1997 8;141(45):2176-9
10. Wyatt KM et al, Efficacy of vitamin B-6 in the treatment of premenstrual syndrome: systematic review, BMJ 1999;318(7195):1375-81
11. Berger AR et al, Dose response, coasting, and differential fiber vulnerability in human toxic
neuropathy: a prospective study of pyridoxine neurotoxicity, Neurology 1992;42(7):1367-70
12. Heap LC et al, Vitamin B status in patients with chronic fatigue syndrome, J R Soc Med 1999;92(4):183-5
13. Schumann K, Interactions between drugs and vitamins at advanced age, Int J Vitam Nutr Res 1999;69(3):173-8
14. Ellis JM et al, Clinical aspects of treatment of carpel tunnel syndrome with B6, Annals NY Acad Sci 1990;585:302-20
15. Ayback M et al, Effect of oral pyridoxine hydrochloride supplementation on arterial blood pressure in patients with essential hypertension, Arzneim Forsch 1995;45:1271-3
16. Vutyavanich T et al, Pyridoxine for nausea and vomiting of pregnancy: a randomized, double-blind, placebo-controlled trial, Am J Obstet Gynecol 1995;173(3 Pt 1):881-4
17. Selhub J et al, Homocysteine metabolism, Annu Rev Nutr 1999;19:217-46

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* The information presented in this web site is intended to inform and educate. It is not intended replace a qualified medical practitioner to diagnose or treat medical conditions.

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