Functions

Vitamin B6 (pyroxidine and related compounds) is involved in protein metabolism as a co-enzyme, breaking down and synthesis of amino acids and in the synthesis of unsaturated fatty acids from essential fatty acids. It converts tryptophan, an amino acid, to serotonin, a neurotransmitter and also stimulates cerebral activity and brain metabolism. It is also involved in hemoglobin synthesis. Essential for normal growth and gynecological health.

Uses

Prevents hypochromic anemia, seborrheic dermatitis, mucous membrane lesions and peripheral neuritis. Essential for normal growth, neurotransmitter synthesis and gynecological health.

Useful in dysmenorrhea; nausea of pregnancy; toxemia of pregnancy; infant seizures; tardive dyskinesia; paniculofibrositis; depression; dementia; hyperkinetic; acne; asthma; anemia--sideroblastic, iron resistant, sickle cell; dec MSG sensitivity; kidney stones; diabetes.

Deficiency

Vitamin B6 deficiencies may result in:

• Greasy, scaly dermatitis; seborrheic dermatitis
• Microcytic anemia
• Abnormal EEG
• Infant seizures
• Depression
• Nausea/vomiting
• Mucous membrane lesions
• Peripheral neuritis
• Hyperirritability
• Altered mobility and alertness
• Poor memory
• Poor utilization of fat, protein, sugar
• Water retention
• Abnormal head movements
• Spinal degeneration
• Macrocytic anemia
• Glossitis
• Fatigue
• Achlorhydria
• Decr. lymphocytes macrophages, PMN, phagocytes
• Still birth if deficient during pregnancy

Antagonists

Vitamin B6 is destroyed by light, cooking and food processing. May be deficient in Isoniazid treatment.

Co-factors

Zinc and riboflavin are required to convert B6 to active forms in the liver. Magnesium is also required.

Drug Interactions

Alcohol increases breakdown of the biologically active form of vitamin B6 and long-term use may cause liver damage which interferes with the conversion of vitamin B6 to the active form. Amphetamines, levodopa, some antidepressants, isoniazid, penicillamine and hydralazine may alter vitamin B6 requirements. Oral contraceptives may also affect vitamin B6 metabolism and increase needs. Large doses of vitamin B6 may interfere with the action of anticonvulsant drugs. Should not be taken by patients on L-dopa or Sinemet.

Dose

RDA: 1.3-2.0 mg/d

Therapeutic: Main: 5 mg; 50mg-3g as required.

Toxicity

Vitamin B6 toxicity may produce hand and foot numbness and lack of muscle coordination.

Sources

Vitamin B6 sources include: peanuts, fish, poulty, meat, bananas, whole grains, egg yolk, legumes, bran; watermelon; banana; chicken; organ meats; yeast; fish; legumes; blackstrap molasses;leafy green vegs.