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PROMOTES Immune System Function Production of Antibodies Immune System Structural Support (spleen and other “lymphoid” tissues Metabolism of Macronutrients (carbohydrates, fats and proteins) Amino Acid Molecules Availability of Building Blocks for the Body Neurotransmitter Production Normal Homocysteine Levels
PROTECTS AGAINST Symptoms of PMS (premenstrual syndrome) Hormonal Fluid Weight Gain Mood Swings Morning Sickness in Pregnant Women*
*Anything taken during pregnancy needs the guidance of a qualified health care professional.
People with busy lives that are frequently under increased amounts of stress need supplementation with all of the B complex vitamins that includes about 15 mg of vitamin B6.
Overview Vitamin B6 exists in three forms. The most widely known is pyridoxine, the other two are pyridoxamine & pyridoxal. It was discovered in 1934 by Paul Gregory. Like all of the B vitamins it is water soluble and is not readily stored in the body so it needs to be ingested regularly. It is also synthesized in small amounts by the beneficial bacteria in the intestines.
It is necessary for the proper functioning of over sixty enzymes in the body. Many of it's activities are related to protein metabolism, the amino acids, along with the unaltered dietary fats in the body providing the building blocks for tissues, organs, hemoglobin, serotonin, various hormones and the prostaglandins.
Two national surveys, one done in 1988-1994 and another in 1994-1996, showed that most Americans diets meet current intake recommendations. One Department of Agriculture study reported that about 80% of Americans consumed less than the RDA for vitamin B6.
Vitamin B6 deficiencies primarily affect the dermatologic, circulatory and the neurological systems. Immune function can be impaired resulting in leukopenia, a decrease in the normal number of white blood cells. Because it has so many metabolic roles, there are a wide variety of deficiency symptoms, including:
-Depression -Dull Alertness -Elevated Homocysteine -Lethargy -Movement/Mobility Alterations -Nausea/Vomiting -Nerve Inflammation (pain, tingling, numbness) -Premenstrual Syndrome -Seborrheic Dermatitis -Sleep Disorder/Disturbance -Tongue & other oral mucosa inflammation (glossitis & cheilosis)
The vitamin B6 antagonist deoxypyridoxine produces many of these symptoms.
A deficiency of vitamin B6 can cause convulsions in infants.
Many antibiotics and diuretics deplete vitamin B6.
Birth control pills and certain hormone drugs can deplete vitamin B6.
Although many prescribed drugs have the most powerful effect of depleting vitamin B6 from the body, there are chemical and substances in the environment which antagonize it and cause depletion. A few of these more prevalent ones are:
-Chemicals that accelerate fruit ripening -PCBs -Rancid Fats -Tobacco Smoke -Yellow dye #5
See DRUG DEPLETION TABLE for specific drug information.
Since vitamin B6 is water soluble, a substantial amount is lost in cooking, particularly boiling. Food processing destroys a large amount of it.
Best Food Source: -Fortified Cereal
Naturally Occurring Sources: -Avocados -Bananas -Beans (fresh and cooked dried) -Broccoli -Cabbage -Cauliflower -Dried fruit -Nutritional yeast -Nuts (esp. peanuts & walnuts) -Oatmeal -Organ meats (liver) -Potatoes -Soybeans -Sunflower seeds -Wheat germ -Whole grains
Fortified Cereal
About 100 enzyme reaction depend on vitamin B6. Many of the enzymes dependent on this micronutrient, particularly the pyridoxal phosphate enzymes, are involved in amino acid metabolism which includes:
-decarbonation (removal of carboxylic acid groups) -desulfuration (transfer of sulfhydro groups) -transamination (transfer of amino groups)
It is needed in the production of numerous neurotransmitters that are derived from amino acids. It is a key factor in the metabolism of homocysteine, an amino acid that when elevated is an independent risk factor for the development of heart disease. It is important for the immune system as it helps maintain the health of lymphoid organs that make white blood cells (WBC's). These organs are the thymus, spleen, and lymph nodes.
Vitamin B6 is essential for the growth of red blood cells (RBC's) and the formation of hemoglobin which carries the oxygen inside the RBC's. It is also essential for the conversion of tryptophan to niacin, vitamin B3.
Elevated homocysteine levels in the blood is now recognized as one of the most critical independent risk factors to the development of cardiovascular disease which causes heart attacks and strokes. Homocysteine, a toxic intermediate metabolite of the amino acid methionine, can directly damage the blood vessel inner lining called the endothelium. These damaged areas scar which leads to a decrease in the flexibility of the arteries, a process called athrosclerosis. Vitamin B6 is one of the nutrients that is required to keep homocysteine from accumulating to higher then normal levels in the blood. Studies are underway to determine how much vitamin B6 in combination with what other substances is most efficacious in bringing down elevated homocysteine levels.
Depression can occur when the synthesis of serotonin, a brain chemical called a neurotransmitter, is inhibited. Vitamin B6 is an essential part in the formation of an enzyme (5-hydroxytryptophan decarboxylase) that initiates catalysis on tryptophan, one of the steps in it's conversion to serotonin.
A reduction in available Vitamin B6 may cause insomnia and other sleep disturbance. Melatonin, a neurotransmitter, vital as a biological trigger for restorative sleep is synthesized in the brain from serotonin. If serotonin synthesis itself is inhibited by lower vitamin B6 levels, there eventually would be a corresponding decrease in the supply of melatonin synthesis.
Premenstrual syndrome, more recently termed premenstrual dysthymic disorder, dysthymia being a state of mild depressive symptoms, is a imbalanced hormonal state of excess estrogen production for an individual. It brings about the characteristic excessive menstrual flow, tender breasts, irregular bleeding and emotional mood swings. A vitamin B6 deficiency causes an increase in estrogen gene expression, a condition resulting in increasing the amount of estrogen in the body beyond what in can utilize properly.
Recommended Dietary Allowance: The RDA -recommended dietary allowance- for vitamin B6 was established in 1998 for adults and reported in milligrams:
-Men and Women 19-50 years of age: 1.3 mg/day. -Men age 51+: 1.7 mg/day -Women age 51+: 1.9 mg/day. -Pregnancy at any age: 1.9 mg/day.
RDA/AI* (Adequate Intake)
AGE (YRS) AMOUNT in milligrams (mg) / day
Infants 0.0-0.5: 0.1 - 0.3* 0.5-1.0: 0.1 - 0.3*
Children 1-3: 0.5 - 0.6 4-8: 0.5 - 0.6
Males 9-13: 1.0 14-18: 1.3 19-30: 1.3 31-50: 1.3 51-70: 1.7 71+: 1.7
Females 9-13: 1.0 14-18: 1.3 19-30: 1.3 31-50: 1.3 51-70: 1.5 71+: 1.5
Pregnant: 1.9
Lactating: 2.0
Vitamin B6 can produce neurotoxicity at doses greater than two grams (2000mg) at one time for a sustained interval. It has been reported at lower doses around 500mg. Symptoms are actually similar for deficiency but are predominantly neurologic with tingling in hands & feet, as well as movement alterations with decreased muscle coordination and stumbling gait. All symptoms resolve with discontinuation of high dose supplementation. |