Populations at Risk for Vitamin B6 Deficiency

The following populations may be at risk for vitamin B6 deficiency and may require a supplement:

• The Elderly—many older adults have low blood levels of vitamin B6, which may occur from low intake of the vitamin or accelerated hydrolysis and oxidation of the vitamin.
• People Who Consume Excessive Amounts of Alcohol—alcohol impairs the conversion and enhances the hydrolysis of the vitamin.
• People Who Smoke Cigarettes—cigarette smoking disturbs vitamin B6 metabolism, which contributes to a deficiency. Studies have shown the vitamin level to normalize within two years of quitting smoking.

Vitamin B6, Homocysteine, and Heart Disease

Homocysteine is an amino acid normally found in the blood. However, studies have shown that elevated blood levels of homocysteine can be a risk factor for heart disease and stroke. Because vitamins B6, B12, and folic acid are required for the metabolism of homocysteine, it is thought that a deficiency of any of the three may increase the level of homocysteine in the blood. One would think that taking these vitamins as supplements may offer protection from heart disease. However, clinical intervention trials are needed to clearly determine this.

Areas of Research That Have Not Been Supported by Clinical Data

• Headache and Depression—vitamin B6 is needed for the synthesis of neurotransmitters, including serotonin. Low levels of serotonin have been found in individuals suffering from depression and migraine headaches. This led researchers to look at the relationship between vitamin B6, headaches, and depression. So far, vitamin B6 supplements have not proved effective in relieving either.
• Premenstrual Syndrome (PMS)—there has been much anecdotal evidence that vitamin B6 can help relieve the symptoms of PMS (depression, irritability, bloating, mastalgia). However, clinical trials have failed to support this idea.
• Carpal Tunnel Syndrome—the idea that vitamin B6 can help with carpal tunnel syndrome has been around for about 30 years. Scientific studies have never been able to show this to be true. In fact, there are documented cases of neuropathy caused by excessive amounts of vitamin B6 taken for carpal tunnel syndrome.
• Morning Sickness—there has been some evidence that high levels of B6 can help allieviate the symptoms, such as nausea, of morning sickness during pregnancy.