Vitamin B6 is one of eight water-soluble B vitamins. It was discovered in the 1930s during nutrition studies on rats. Vitamin B6 is exists in three major chemical forms: pyridoxine, pyridoxal, and pyridoxamine. Vitamin B6 performs as a coenzyme to carry out metabolic processes that affect the body’s use of protein, carbohydrates, and fat. Vitamin B6 also is involved in metabolism of protein and carbohydrates, the production of insulin, red and white blood cells.
Vitamin B6 is an especially important vitamin for maintaining healthy nerve and muscle cells. It is also take part in the production of DNA and RNA, the body's genetic material. Vitamin B6 is necessary for proper absorption of vitamin B12 and for the production of red blood cells and cells of the immune system. It also helps to convert tryptophan to niacin, and may be found in nuts, meat, fish, eggs, wheat germs, milk, and whole grain foods.
Vitamin B6 can be found in, avocados, bananas, carrots, fortified cereals, green bean, hazelnuts (filberts), lentils, potatoes, salmon, shrimp, soybeans, spinach, sunflower seeds.
The daily Recommended Dietary Allowance (RDA) of vitamin B6 is various depend on age. For men and women between 19-50 years old can take 1.3 mg. Women over 50 years old need 1.5 mg, while men need 1.7 mg. An additional between 0.1-0.7 mg is needed during the pregnancy and lactation period. High amounts (100–200 mg per day or even more) may be recommended for certain conditions.
Deficiency of vitamin B6 is rare, since most foods eaten contain this vitamin. Signs of a Vitamin B6 deficiency include peeling skin (dermatitis), cracked and sore lips, inflamed tongue and mouth, neuropathy, depression, anxiety, loss of libido, insomnia, water retention, inability to process glucose, itchy, body weight loss/gain, weakness, mental confusion, irritability, nervousness, inability to sleep, hyperactivity, anemia, skin lesions, and kidney stones. It is important to have a physician evaluate these symptoms so that appropriate medical care can be given.
Vitamin B6 is usually safe, at intakes up to 200 mg per day in adults. However, sustained periods of large doses may cause irreversible nerve damage. The excess of vitamin B6 may also lead to kidney stone formation. Although vitamin B6 is a water-soluble vitamin and is excreted in the urine, very high doses of vitamin B6 over long periods of time may result in painful neurological symptoms known as sensory neuropathy. Symptoms of a pyridoxine overdose may include poor coordination, staggering, numbness, decreased sensation to touch, temperature, and vibration, and tiredness for up to six months.
