Vitamin B6 is the master vitamin for processing amino acids—the building blocks of all proteins and some hormones. Vitamin B6 helps to make and take apart many amino acids and is also needed to make the hormones, serotonin, melatonin, and dopamine.
Where is it found?
Potatoes, bananas, raisin bran cereal, lentils, liver, turkey, and tuna are all good sources of vitamin B6.
Vitamin B6 has been used in connection with the following conditions (refer to the individual health concern for complete information):
Who is likely to be deficient?
Vitamin B6 deficiencies are thought to be very rare. Vitamin B6 deficiency can cause impaired immunity, skin lesions, and mental confusion. A marginal deficiency sometimes occurs in alcoholics, patients with kidney failure, and women using oral contraceptives. Some doctors believe that most diets do not provide optimal amounts of this vitamin. People with kidney failure have an increased risk of vitamin B6 deficiency.1 Vitamin B6 has also been reported to be deficient in some people with chronic fatigue syndrome.2
How much is usually taken?
The most common supplemental intake is 10–25 mg per day. However, high amounts (100–200 mg per day or even more) may be recommended for certain conditions.
Are there any side effects or interactions?
Vitamin B6 is usually safe, at intakes up to 200 mg per day in adults.3 However, neurological side effects can sometimes occur at that level.4 Levels higher than 200 mg are more likely to cause such problems. Vitamin B6 toxicity can damage sensory nerves, leading to numbness in the hands and feet as well as difficulty walking. The National Academy of Sciences performed an analysis of vitamin B6 studies. They determined the safe upper limit for long-term use is 100 mg per day. However, under supervision of a healthcare professional, up to 200 mg per day of vitamin B6 can be safely taken by most men and nonpregnant women for limited periods of time. Pregnant and breast-feeding women should not take more than 100 mg of vitamin B6 per day without a doctor’s supervision.
Since vitamin B6 increases the bioavailability of magnesium, these nutrients are sometimes taken together.
Are there any drug interactions?
Certain medicines may interact with vitamin B6. Refer to drug interactions for a list of those medicines.
References
1. Makoff R. Vitamin replacement therapy in renal failure patients. Miner Electrolyte Metab 1999;25:349–51 [review].
2. Heap LC, Peters TJ, Wessely S. Vitamin B status in patients with chronic fatigue syndrome. J R Soc Med 1999;92:183–5.
3. Gaby AR. Literature review & commentary. Townsend Letter for Doctors June 1990;338–9.
4. Parry G, Bredesen DE. Sensory neuropath with low-dose pyridoxine. Neurology 1985;35:1466–8.
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2006-09-07
