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Vitamin B-6 (Pyridoxine, pyridoxal phosphate)Vitamin B6 plays a role in making proteins, hormones, and neurotransmitters. Because mild deficiency of vitamin B6 is common, this is one vitamin that is probably worth taking as insurance. However, there is little evidence that taking vitamin B6 above nutritional needs offers benefits in the treatment of any illnesses, except, possibly, nausea of pregnancy (morning sickness). Vitamin B6 requirements increase with age. The official U.S. recommendations for daily intake are as follows: Infants 0–6 months, 0.1 mg B6 deficiency might be worsened by use of hydralazine (for high blood pressure),5penicillamine (used for rheumatoid arthritis and certain rare diseases),6theophylline (an older drug for asthma),7-11MAO inhibitors, and the antituberculosis drug isoniazid (INH), all of which are thought to interfere with B6 to some degree. Good sources of B6 include nutritional (torula) yeast, brewer's yeast, sunflower seeds, wheat germ, soybeans, walnuts, lentils, lima beans, buckwheat flour, bananas, and avocados. One study found that 30 mg of vitamin B6 daily was effective for symptoms of morning sickness.17 While far above nutritional needs, this dosage should be safe. However, for the treatment of other conditions, B6 has been recommended at doses as high as 300 mg daily. There are potential risks at this level of vitamin B6 intake (see the Safety Issues section below for more information). The results of a large double-blind, placebo-controlled study suggest that vitamin B6 at a dose of 30 mg daily may be helpful for treating nausea in pregnancy (morning sickness). Vitamin B6 has been proposed for numerous other uses as well, but without much (if any) scientific substantiation. For example, the two most famous uses of vitamin B6, carpal tunnel syndrome and PMS, have no reliable supporting evidence at all, and the best designed studies found it ineffective for either of these purposes. Higher intake of vitamin B6 reduces the level of homocysteine in the blood, a substance that might accelerate cardiovascular disease (heart disease, strokes, and related conditions.) However, there is as yet no meaningful evidence that reducing homocysteine is beneficial, and considerable evidence that it is not. See the full homocysteinearticle for more information. For the following other conditions, current evidence for benefit with vitamin B6 remains incomplete and/or contradictory: allergy to monosodium glutamate (MSG), asthma,depression,diabetes of pregnancy, HIV infection, photosensitivity, preventing kidney stones, schizophrenia, seborrheic dermatitis,tardive dyskinesia and other side effects of anti-psychotic drugs, and vertigo. Despite some claims in the media, vitamin B6 has not shown benefit for enhancing mental function. One study failed to find B6 at a dose of 50mg daily helpful for rheumatoid arthritis (despite a general B6 deficiency seen in people with this condition). Vitamin B6, alone or in combination with magnesium, showed some early promise for the treatment of autism, but the best designed studies failed to find it effective. Additionally, current evidence suggests that vitamin B6 is not effective for treating diabetic neuropathy or eczema or for helping control the side effects of oral contraceptives. Morning Sickness (Nausea and Vomiting in Pregnancy) Vitamin B6 supplements have been used for years by conventional physicians as a treatment for morning sickness. In 1995, a large double-blind study validated this use.38 A total of 342 pregnant women were given placebo or 30 mg of vitamin B6 daily. Subjects then graded their symptoms by noting the severity of their nausea and recording the number of vomiting episodes. The women in the B6 group experienced significantly less nausea than those in the placebo group, suggesting that regular use of B6 can be helpful for morning sickness. However, vomiting episodes were not significantly reduced. Another study found vitamin B6 and ginger equally effective for morning sickness. However, as ginger is not a proven treatment for this condition, this study by itself does not provide any additional evidence in favor of B6. Premenstrual Syndrome (PMS) A recent, properly designed double-blind study of 120 women found no benefit of vitamin B6 for PMS.39 In this study, three prescription drugs were compared against vitamin B6 (pyridoxine, at 300 mg daily) and placebo. All study participants received 3 months of treatment and 3 months of placebo. Vitamin B6 proved to be no better than placebo. Approximately a dozen other double-blind studies have investigated the effectiveness of vitamin B6 for PMS, but none were well designed, and overall the evidence for any benefit is weak at best. Some books on natural medicine report that the negative results in some of these studies were due to insufficient B6 dosage, but in reality there was no clear link between dosage and effectiveness. However, preliminary evidence suggests that the combination of B6 and magnesium might be more effective than either treatment alone.42 Autism One double-blind, placebo-controlled crossover study found indications that very high doses of vitamin B6 may produce beneficial effects in the treatment of autism.34 However, this study was small and poorly designed; furthermore, it used a dose of vitamin B6 so high that it could cause toxicity. It has been suggested that combining magnesium with vitamin B6 could offer additional benefits, such as reducing side effects or allowing a reduced dose of the vitamin. However, the two reasonably well-designed studies using combined vitamin B6 and magnesium have failed to find benefits.58-60 Therefore, it isn’t possible at present to recommend vitamin B6 with or without magnesium as a treatment for autism. Asthma A double-blind study of 76 children with asthma found significant benefit from vitamin B6 after the second month of usage.43 Children in the vitamin B6 group were able to reduce their doses of asthma medication (bronchodilators and steroids). However, a recent double-blind study of 31 adults who used either inhaled or oral steroids did not show any benefit.44 The dosages of B6 used in these studies were quite high, in the range of 200 to 300 mg daily. Because of the risk of nerve injury, it is not advisable to take this much B6 without medical supervision (see Safety Issues). The safe upper levels for daily intake of vitamin B652 are as follows: Children 1–3 years, 30 mg In addition, doses of vitamin B6 over 5 mg may interfere with the effects of the drug levodopa when it is taken alone.48-50 However, vitamin B6 does not impair the effectiveness of drugs containing levodopa and carbidopa. Maximum safe dosages for individuals with severe liver or kidney disease have not been established.
The Fountain of Youth?What if I told you that it may be possible for you to live to age 100 or even longer, in better health than you are in right now? And, if you are already experiencing the ill effects of aging, what if I told you that it may be possible for you to look and feel 20 years younger and stay that way beyond the age of 100. Aside from the fact that you'd probably call me crazy, I have to tell you that we have never been as close as we are today to actually being able to extend human life!
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