Vitamin B6: How A Deficiency In One Essential Nutrient Could Quadruple Your Risk Of Stroke

The benefits of vitamin B6 are wide ranging - from supporting protein metabolism and muscle growth to overcoming premenstrual symptoms and depression by encouraging the production of 'feel-good' chemicals, such as serotonin and dopamine, in the brain that help maintain emotional balance.

It is important to be aware that vitamin B6 comes in different forms and the type found in most multivitamin supplements is an inactive and cheaper form called pyridoxine hydrochloride, rather than the active form: pyridoxal-5-phosphate (P5P). This doesn't necessarily pose a problem since pyridoxine is converted in your liver to the active form P5P - the only form your cells can use, which goes to work straight away in your blood stream.1

However, this transformation is not always successful and a lack of the mineral magnesium in the diet or an underactive liver (due to too much alcohol, antibiotics or a generally unhealthy lifestyle) can soon interfere with this process. If this happens then large amounts of pyridoxine can soon accumulate in the body that cannot be utilised, which can cause nerve damage over time.2

It also causes a deficiency of P5P, which can have negative consequences in terms of your health and result in depression, mood swings, muscle weakness, fatigue, hair loss, worsening of premenstrual symptoms, and poor appetite.

So, instead of relying on ordinary vitamin B6 (pyridoxine) being converted properly to P5P in your body, it is best to take pure P5P in the first place. Better still, P5P possesses even more health-related benefits compared to the inactive form of vitamin B6. In addition to helping the conditions outlined above, it has also been shown to improve carpal tunnel syndrome (compression of the nerves in the wrist causing numbness and pain in the hand), and helps control homocysteine levels that in turn helps prevent cardiovascular disease, stroke and arthritis.

P5P helps keep homocysteine levels in check - reducing the risk of heart disease and stroke
P5P appears to be able to help disperse and inactivate a substance called homocysteine. If you're a long-time HSI member or reader of the daily health email alerts you'll know why this is so vital, as homocysteine promotes the build-up of plaque on blood vessel walls, which increases coagulation (clotting).

So it's no surprise then that a high homocysteine level can significantly increase your risk of suffering a heart attack or stroke. Recent research has revealed that homocysteine may be one of the biggest culprits responsible for causing these conditions - possibly more so than cholesterol. If you'd like to receive the FREE daily health email alerts for more updates like this, then simply click on the Register link, above left.

Scientists from the Department of Neurology, Massachusetts General Hospital in the US, have found that levels of P5P in stroke patients is about half that of healthy individuals. Having these low P5P levels has been shown to increase the risk of stroke by up to four-fold.3

The US scientists believe that the increased risk of stroke is due to high homocysteine levels that deficient supplies of P5P are unable to lower. It follows that supplementing with P5P, therefore boosting the body's own levels of this nutrient, helps lower homocysteine and reduces the risk of stroke.

Low P5P levels also implicated in Parkinson's disease and rheumatoid arthritis
Homocysteine levels have also been found to be high in Parkinson's disease patients who are taking the drug L-dopa. This is a commonly prescribed drug for treating the disease but it has one serious drawback - it causes homocysteine levels to rise. So it is vital to keep homocysteine levels low in these patients, in order to prevent an additional illness like cardiovascular problems from developing.

Dr J. Miller and co-workers from the Vitamin Bioavailability Laboratory, Human Nutrition Research Centre on Ageing, Tufts University in the US, studied 40 Parkinson's disease patients and found that those who had high homocysteine levels also had low concentrations of P5P in their blood. This tallies with the research findings already mentioned and confirms that when levels of P5P are low homocysteine rises.

Dr Miller concluded: 'The vitamin B requirements necessary to maintain normal homocysteine concentrations are higher in patients who are on L-dopa. Vitamin B (P5P) supplements may be warranted for Parkinson's disease patients'.4

In another clinical trial, US scientists from the Cooper Institute for Aerobics Research in Dallas, Texas, studied 150 volunteers who agreed to take a daily vitamin preparation containing P5P (25 mg), folic acid (5mg) and vitamin B12 (50 micrograms). They found that after 12 weeks of treatment, concentrations of P5P in the blood were significantly increased and that homocysteine levels plummeted by up to 25 per cent.5

Patients with rheumatoid arthritis also tend to have low levels of P5P in their blood. Researchers from the Human Nutrition Research Centre, Tufts University, Boston, in the US, studied 33 patients with the disease. They measured P5P concentrations in the patients' urine, blood and red blood cells. They found that low levels of P5P are significantly implicated in cases of rheumatoid arthritis.6

What to take for best results
The recommended dosage amount for the maintenance of overall health is 20-25mg of P5P daily. For the treatment of specific diseases, the dosage can be increased to 50mg three times a day - this amount should only be taken under proper medical supervision. Pregnant and breast-feeding women should only take P5P following medical advice. As always it is extremely important that you consult your doctor before taking P5P if you are currently on any medication.

1. Bor MV et al. Clin Chem 2003, 49(1):155-161
2. Wang H, Kuo M, Brain Res Bull 2002, 58(6):541
3. Kelly PJ et al. Stroke 2003, 34(6):e51-54
4. Miller JW et al. Neurology 2003, 60(7):1125-1129
5. Earnest C, Cooper KH, et al Nutrition 2002, 18(9):738-742
6. Chiang EP et al. J Nutr 2003,133(4):1056-1059