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.
Reliable
and relatively consistent scientific data showing a substantial health benefit. Contradictory, insufficient, or preliminary studies
suggesting a health benefit or minimal health benefit. For an herb, supported by traditional use but minimal
or no scientific evidence. For a supplement, little scientific support and/or minimal health
benefit.
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 (To view, roll mouse over the "References" heading; to hide, click on the heading)
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.
The information presented in Healthnotes is for informational purposes
only. It is based on scientific studies (human, animal, or in vitro), clinical
experience, or traditional usage as cited in each article. The results reported may not
necessarily occur in all individuals. For many of the conditions discussed, treatment with
prescription or over the counter medication is also available. Consult your doctor,
practitioner, and/or pharmacist for any health problem and before using any supplements or
before making any changes in prescribed medications. Information expires June 2009.
