Vitamin B
6 (
pyridoxine) is a water-soluble vitamin necessary for many different chemical reactions in the body. It is claimed to be beneficial for a variety of different uses (although some uses are more credible than others).
The main role of vitamin B6 in the body is to work as a coenzyme in numerous different chemical reactions. This means that vitamin B6 helps enzymes to work properly. It is important for a wide variety of reactions, including the metabolism of amino acids, carbohydrates, and lipids.
Vitamin B6 is also important for the formation of hemoglobin, an important part of red blood cells. This is why low vitamin B6 can lead to anemia.
Low vitamin B
6 can increase levels of homocysteine, an amino acid that can cause problems if it builds up to high levels. In particular, it is thought that high homocysteine may contribute to problems such as
cardiovascular disease or blood clots. Vitamin B
6 decreases homocysteine levels after meals (but does not really affect fasting homocysteine levels). Low levels of vitamin B
6 may also increase levels of C-reactive protein (CRP), an inflammatory molecule that may be related to
heart disease and several other medical conditions.
The vitamin may also have antioxidant properties. In addition, it may decrease
kidney stone formation by decreasing the amount of oxalate (a component of some
types of kidney stones) excreted in the urine. It is also thought that vitamin B
6 may increase levels of the neurotransmitter serotonin, which is why some people think it may be useful for treating
depression or attention deficit hyperactivity disorder (
ADHD).
As you might expect, this vitamin is effective for treating vitamin B
6 deficiency (and related problems). It may also be useful for treating hyperhomocysteinemia. There is not enough evidence to suggest that it works for most other uses
(see Does Vitamin B6 Work? for more information).
Because it has been studied quite a bit, good information about vitamin B6 dosing is available. For some of the less studied uses, the most effective (and safe) doses have not yet been established. Recommended Dietary Allowances (RDAs) and Tolerable Upper Intake Levels (UL) have been established for the vitamin.
Side Effects of Vitamin B6
Some people think that vitamins are naturally free of side effects. However, this is simply not the case. Vitamin B6 has been reported to cause various side effects, including (but not limited to):
- Nausea
- Vomiting
- Abdominal pain (stomach pain)
- Headaches
- Tingling, numbness, or other unusual sensations in the hands or feet.
(Click Vitamin B6 Toxicity to learn more, including any potentially serious side effects that you should report immediately to your healthcare provider.)
Most people can safely take vitamin B6. Some people may be more likely to experience problems due to the vitamin. Therefore, you should talk with your healthcare provider prior to taking the supplement if you:
Make sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
(Click Vitamin B6 Safety for more information, including any available warnings and precautions.)
What If I Take a Vitamin B6 Overdose?
It is possible to take too much vitamin B6. Overdose symptoms may vary, depending on factors such as the dosage and whether it was taken all at once (a single massive overdose) or over a long period of time (a chronic overdose).
