What Is Vitamin B-6?
Vitamin B-6 is a member of the vitamin B family, made up of 6 chemical compounds:
- pyridoxine 5-phosphate
- pyridoxal 5-phosphate
- pyridoxamine 5-phosphate
The US FDA and the Canadian Food Inspection Agency have set their Recommended Daily Intake (RDA) at 2mg and 1.8mg respectively. This recommended intake may easily be obtained from a healthy diet; however, some people may be at deficiency risk due to disease or alcohol dependency.
Persons suffering from renal disease or those who have undergone a kidney transplant are at risk of not obtaining adequate amounts of vitamin B-6. Others at risk of vitamin B-6 deficiency are those with autoimmune disorders, people who are obese, and those suffering from genetic diseases such as homocystinuria (also known as CBS deficiency).
Symptoms of vitamin B-6 deficiency include anemia, dermatitis, scaling on the lips and cracks on the corners of the mouth, swollen tongue, depression, confusion, and a weakened immune system. In infants, the symptoms of this deficiency show as irritability and seizures .
Vitamin B-6 is found naturally in a variety of foods, as well as in foods enriched with the vitamin. It is also available as a dietary supplement, in the form of pyridoxine hydrochloride, in either multivitamins or B-complex vitamins.
Facts About Vitamin B-6
- All forms of vitamin B-6 can be converted into the other forms.
- Pyridoxal 5-phosphate is used to synthesize dopamine and serotonin, two major chemicals associated with feelings of pleasure.
- Approximately 28-36 percent of the US population obtain vitamin B-6 from supplements.
Foods Containing Vitamin B-6
Foods rich in vitamin B-6 include chicken breast, turkey breast, beef, pork, tuna, salmon, shrimp, pistachio nuts, pinto beans, sunflower seeds, sesame seeds, chickpeas (garbanzo beans), milk, cheese, avocado, bananas, brown rice, wheat flour, bran and fortified breakfast cereal.
Is Vitamin B-6 Ever Bad For You?
Vitamin B-6 is used in over 100 enzymatic reactions which are critical for the normal functioning of the body. The following table represents the US Recommended Daily Intake and Upper Intake levels for various age groups:
|Age/Gender/Condition||Recommended Daily Intake||Upper Intake Level|
|Infants 0-12 months||0.1-0.3 mg||not established|
|Children 1-13 years||0.5-1.0 mg||30-50 mg|
|Teens 14-18 male/female||1.3 mg / 1.2 mg||80 mg|
|Adults 19-50||1.3 mg||100 mg|
|Adults 51+ male/female||1.7 mg / 1.5 mg||100 mg|
|Pregnant/Lactating||1.9 mg / 2.0 mg||80-100 mg|
While vitamin B-6 is critical in one’s diet, care should be taken when obtaining it from dietary supplements, as adverse effects are associated with excessive intake. When supplements are taken in excess neurological disorders may result, which are characterized by loss of control of body movement. Other symptoms include painful skin lesions, nausea, heartburn, abdominal pain, headache, loss of appetite and sensitivity to light.
Benefits Of Vitamin B-6
Vitamin B-6 is vital in the prevention of heart attack and stroke, due to the fact that it helps regulate homocysteine in the blood, the compound linked to inflammation and development of heart disease—a contributing factor of heart attack.
Vitamin B-6 may help in improving brain function as studies indicate a correlation between adequate intake of vitamin B-6 and a boost in memory retention. Furthermore, vitamin B-6 aids in overall mental health, as it helps in the production of dopamine and serotonin, major mood enhancers.
Pyridoxal 5-phosphate aids in the synthesis and binding properties of hemoglobin, resulting in increased oxygen reaching the red blood cells.
Vitamin B-6 may also help in the reduction of aches and pains associated with Rheumatoid arthritis.
PMS Symptom Relief
Studies show that pyridoxine has proven to be effective in treating symptoms of premenstrual syndrome. A daily dose of 80mg taken for three months has shown to effectively reduce symptoms such as moodiness, irritability, bloating and anxiety.
Nausea Relief During Pregnancy
Furthermore, vitamin B-6 has also been useful in the treatment of nausea during pregnancy. The American Congress of Obstetrics and Gynecology recommends a dosage of 10-25mg of vitamin B-6 to be taken 3 or 4 times daily in order to alleviate morning sickness during pregnancy. If this does not correct the problem, then doxylamine may be added as a second course of treatment. As with all supplements, you should check with your doctor before adding or changing dosages.
Different compounds of vitamin B-6 are involved in several bodily metabolisms: namely amino acid metabolism, lipid metabolism, glucose metabolism and gene expression.
Negative Impact of Vitamin B-6 on the Body
Side effects have been associated with vitamin B-6 obtained from dietary supplements, but not from food sources. Adverse reactions, such as irreversible neurological disorders characterized by a reduction in mobility may result from prolonged exposure to excessive intake of vitamin B-6.
Other side effects of intake higher than the recommended upper limit include nausea, vomiting, stomach pain, loss of appetite, headache, tingling and sleepiness. Pregnant women should avoid taking excessive amounts of vitamin B-6 as this may cause seizures in newborns.
How To Minimize Exposure
Adverse side effects are only associated with vitamin B-6 obtained from dietary supplements; therefore care should be used when taking B-complex supplements and multivitamins.
Should You Worry About Vitamin B-6?
Care should be exercised if you are taking certain medications to treat tuberculosis and other conditions. The antibiotic cycloserine (Seromycin) is used to treat tuberculosis, but when taken with B6 supplements the intensity of seizures and neurotoxicity may be increased.
Other drug interactions include amiodarone—common brands are Cordarone, Nexterone, and Pacerone. This drug is used to treat an irregular heartbeat, but it also makes the skin sensitive to sunlight. Taking vitamin B-6 supplements with amiodarone may increase this sensitivity, increasing risk of sunburn, blistering and rash.
Vitamin B-6 is critical for the proper functioning of the body; it is involved in numerous metabolic reactions that form important compounds needed for normal brain activity and other vital processes. There are no adverse health effects associated with the recommended amounts obtained from food sources.
There is concern, however, when taking dietary supplements, due to the serious side effects associated with them—including serious and irreversible nerve and brain damage. Vitamin B-6 supplements should only be taken under careful supervision of a physician or health care provider who is able to monitor dosage and side effects, especially if you are suffering from a particular disease or are pregnant. Vitamin B-6 can interact negatively with certain medications as well. Any adverse reactions should be reported to the health care provider immediately.