The functions of vitamin B6 are protein metabolism, blood cell synthesis, carbohydrate metabolism, neurotransmitter synthesis, it keeps homocysteine levels low and helps convert tryptophan to niacin.
What does that mean? Vitamin B6 helps us feel more energetic and helps us break down carbs, make blood cells and makes neurotransmitters that regulate mood, sleep, anxiety, appetite, stress hormones and other mood related functions. Homocysteine is normally produced by meat consumption and elevated levels of it can cause heart problems that can lead to long term health problems. As we know niacin is a nutrient that we need for a lot of functions.
Recommended Daily Allowance (RDA)
The recommended daily allowance of vitamin B6 for all sexes aged 19 – 50 is 1.3 milligrams per day. Men aged 51 and up are recommended to take 1.7 milligrams per day. Women aged 51 and up are recommended to take 1.5 milligrams per day.
Sources of vitamin B6 are fortified cereals, mixed foods containing meat, fish or poultry, white potatoes and other starchy veggies, non-citrus fruits, beef liver, organ meats and fortified soy-based meat substitutes are also good sources. Enrichment/fortification does not replace vitamin B6 so it is not in enriched products; therefore, whole grains are the best source.
Vitamin B6 deficiency is rare. When it occurs, microcytic hypochromic anemia, seborrheic dermatitis and neurological symptoms such as depression, confusion and convulsions result. Alcoholism boosts the risk of deficiency. Vitamin B6 is not stable and is sensitive to temperature. Heat can destroy 50% of a food’s vitamin B6 content. 75% of vitamin B6 is bio-available if your diet is varied and when taken as a supplement on an empty stomach is almost completely absorbed, even when taken in mega doses.
Mega doses of vitamin B6 that are greater than or equal to 2000 milligrams per day can cause irreversible nerve damage. Some women take mega doses to alleviate PMS symptoms but this has not been proven to be effective. Some women take mega doses to relieve carpel tunnel but B6 has not been proven to improve this condition.
Toxicity is rare so there is no toxic dose but there is an upper limit. The upper limit has been set at 100 milligrams per day.
USDA.gov. United States Department of Agriculture, 27 Jan. 2012. Web. 27 Jan. 2012. <http://www.fns.usda.gov/tn/Resources/appendd.pdf>.
Insel, Paul M., R. Elaine. Turner, and Don Ross. Nutrition. 3rd ed. Sudbury, MA: Jones and Bartlett, 2007. Print.