Vitamin B6
B6 was discovered in 1926, named in 1936, and its chemical structure finally determined in 1939. German scientists, who made the discovery, called the substance "adermin," but it was American researchers who gave it the name that now stands -- "Pyridoxine." It was named as a result of its chemical structure -- a pyridine ring (5 carbons and 1 nitrogen) and 3 hydroxy groups. Gyorgy, a Hungarian scientist, credited with doing the most work on the substance, preferred the American name, and so pyridoxine it became. Most commercial labels list it as "pyridoxine hydrochloride."
B6 actually consists of a group of chemically related compounds that are metabolically interchangeable: pyridoxine (the alcohol form), pyridoxal (the aldehyde form), and pyridoxamine (the amine form). All three forms can be converted into the active coenzyme pyridoxal phosphate, needed for more than 100 enzymes involved in the metabolism of carbohydrates, fats, and proteins. Pyridoxine is the main form of B6, with all three found in all plant and animal tissues. It is readily and completely absorbed although blood levels tend to be low and storage in the body very limited.
B6 plays a role in the synthesis of RNA and DNA, as well as in cell multiplication including the production of RBC's (making HEME, the red pigment of hemoglobin). It is also essential for the proper absorption of B12, magnesium, and protein and in the formation of hydrochloric acid.
B6 assists in the production of non-essential amino acids and in the breaking down of most proteins. It is vital in supporting the immune system and for the formation of certain neurotransmitters (brain chemicals) from the supplied amino acids. Too much B6 can injure the nerves. On the other hand, the nervous system and the brain would cease to function properly without it.
B6 is the most crucial of all the B Vitamins in maintaining a healthy immune system, with B6-free diets markedly decreasing the antibody response to immunization. Deficiencies diminish immune system function, most notably seen in those suffering from cancer and AIDS. These patients display depressed immune systems coupled with having low levels of several nutrients, including B6. Supplementation of B6 in the elderly has not only boosted the immune system but reduced cancerous growths. B6 applied topically as a cream has reduced melanomas, a skin cancer proven to be highly resistant to treatment. However, sitting in the sun after taking high doses of B6 can produce a skin rash.
B6 has demonstrated the ability to relieve symptoms of PMS, which affects several hormones involving the mentrual cycle. It has also been used to correct some imbalances caused by estrogen-type birth control pills, along with correcting some infertility problems. B6 therapy has been used to abolish infantile seizures stemming from certain inherited metabolic disorders, and has increased glucose tolerance to where lesser amounts of insulin was required. Many women who use oral contraceptives experience the same type of abnormal tryptophan metabolism as diabetics. B6 supplementation can usually reverse this situation, returning gluclose tolerance levels to normal, as well as proving successfull in reducing insulin dosage in diabetics.
B6 has displayed its effectiveness in treating carpal tunnel syndrome when there is a nerve compression involved in the wrist. This method of treatment must be done under supervision since it requires large doses over several months and must be balanced with other members of the B family to prevent other deficiencies. B6 can also alleviate peripheral neuopathy, a side effect of diabetes that damages the nerves in the extremeties.
In cardiovascular disease, B6 has been shown to decrease the "stickiness" of platelets in the blood, thereby reducing the risk of blood clots. Atherosclerosis is likely a result of an accumulaton of excess amounts of an amino acid breakdown product -- which is just one of the problems when B6 is not available or unable to perform its function.
Some forms of arthritis and joint pain respond to B6 supplementation, and, when used with magnesium, B6 can lower the risk of calcium oxalate kidney stones, the most common kind. B6 deficiency can also produce such mental symptoms as anxiety, irritability, and insomnia, and has been linked to long-term memory loss and senility in older people. In addition, low B6 levels are common among asthma sufferers.
One of the most common nutritional deficiencies is B6. Those most at risk are the elderly, pregnant or lactating women, and those with alcohol or chemical dependencies. B6 deficiency can be brought on by using such drugs as anticonvulsants, corticosteroids, estrogens, isoniazid, penicillamine, and hydralazine, which inactivate B6. Phenobarbital (an anticonvulsant) causes deficiencies in several B vitamins, as well as Vitamin C, Vitamin D, magnesium, and calcium. In addition, B6 can interfere with the effectiveness of such drugs as L-dopa, used to treat Parkinson's. Smoking depletes or prevents the uptake of B6, as well as the other B vitamins. High protein diets can also increase the need for B6. Deficiencies of such other nutrients as magnesium, zinc, and riboflavin (B2) can also affect B6 levels.
Up to forty drugs are known to affect the availability or metabolism of B6. Foremost among these is the prolonged use of antituberculosis drug, isoniazid. Others include penicillamine (a chelating agent used in the treatment of copper, mercury, and lead poisoning as well as rheumatoid arthritis), cycloserine (an immuno-suppressant drug); hydralazine (an antihypertensive medication), and such chemical contaminants as "hydrazides and hydrazines." Derivatives of these chemicals appear in cigarette smoke and food additives. Supplements of B6 alleviate some of the adverse effects of these drugs. On the other hand, B6 speeds up the metabolism of L-dopa, lessening its effectiveness in treating Parkinson's disease.
A mild deficiency of B6 is sometimes associated with lowered immunity and nervous disorders. But a severe deficiency is associated with depression, confusion, convulsions, inflammed mouth and tongue, and some skin disorders.
RDA -- adults 25-50 years is 2 mg. for men and 1.6 mg. for women. It has been found that older adults (61-71 years old) require more than the RDA -- and usually most other individuals as well since the consumption of highly processed foods contribute to nutrient deficiencies. Up to 70% of B6 is lost in freezing and processing foods, including luncheon meats, with as much as 90% lost in the milling of cereal grains.
B6 is relatively safe in oral doses of up to fifty times the RDA (approximately 2 mg. per day for adults). Higher doses should have professional guidance since excessive amounts can damage the nervous system, leading to peripheral neuropathy (numbness of hands and feet). Insomnia, nervousness, tremors, and anxiety are also signs of excessive intake.
Mega doses (2-6 grams per day for 2-4 months) have been blamed for progressive sensory ataxia (poorly judged movements that become worse when the eyes are closed. This test is also used in determining awareness of suspected drunk drivers). As well, mega doses can produce profound lower limb impaired sense of position and vibration with touch, temperature, and pain less affected. However, these same symptoms have been produced with supplementations of as little as 100 mg. per day. Therefore, it is an individual matter which must be determined after careful examination of a knowledgeable health care provider. Recovery is slow and only partial following cessation of megadoses of B6.
Summary:
Other names include: adermin, yeast eluate factor, factor Y, Vitamin Y.
Forms include: pyridoxine, pyridoxamine, pyridoxal.
Inhibitors include: long storage, canning, roasting/stewing of meats, water, food processing, alcohol, estrogen, alkali, ultraviolet light, penicillamine, cortisone, prednisone, Isoniazid/INH.
Helpers include: Vitamin B1, B2, B5, F, C, magnesium, potassium, sodium.
Deficiencies produce: (Rebound deficiency can occur if large doses are halted abruptly); convulsions, abnormal brain waves, confusion, mental retardation in infants, mental heal deterioration, nervousness, insomnia, deterioration of dream recall, nervous system deterioration, pain sensitivity, muscle pain, numbess, temporary limb paralysis, cramps, tendon/ligament difficulties, arthritis, unexplained swellings, water retention, increased urination, increased xanthurenic acid in urine, increased Vitamin C in urine, nausea, motion sickness, anemia, decreased blood sugar and glucose tolerance, fatigue, depression, stress, emotional agitation, deterioration of protein synthesis and supply to the brain, cracks around the mouth and eyes, glossy tongue, scaling lips, inflammed gums, mouth sores, decreased immunity, greasy or cheesy sking oozing, oily hair, skin inflammation, dandruff, sparse hair, visual deterioration, decreased hemaglobin production, heart disease, increased cholesterol, atherosclerosis,
decreaed levels of coenzyme pyridoxal phosphate, decreased lymph cell count.
Toxicities produce: decreased sensations in the extremeties, suppressed lactation, emotional agitation; in moderate toxicity is an icreased dream recall.
Note: Pregnant women should consult a medical practisioner before taking more than 50 grams. Extra supplementation should not be taken by anyone taking L-dopa (but it is OK with Sinemet) nor by anyone taking tryptophan for depression as it will convert to B3 producing a B6 deficiency.
Provitamin B6 is the same as Vitamin B13.
