Many foods contain vitamin B6, but extensive processing can remove the vitamin.
People may have seizures, a scaly rash, a red tongue, cracks in the corners of the mouth, or a pins-and-needles sensation in the hands and feet.
The diagnosis is based on symptoms, the presence of possible causes, and response to vitamin B6 supplements.
Vitamin B6 supplements, taken by mouth, can correct the deficiency.
Vitamin B6 (pyridoxine) is essential for the processing (metabolism) of carbohydrates Carbohydrates Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram (1/28 ounce)... read more , amino acids Proteins Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram (1/28 ounce)... read more , and fats Fats Carbohydrates, proteins, and fats supply 90% of the dry weight of the diet and 100% of its energy. All three provide energy (measured in calories), but the amount of energy in 1 gram (1/28 ounce)... read more (lipids), as well as for normal nerve function and for the formation of red blood cells. It also helps keep the skin healthy. (See also Overview of Vitamins Overview of Vitamins Vitamins are a vital part of a healthy diet. The recommended dietary allowance (RDA)—the amount most healthy people need each day to remain healthy—has been determined for most vitamins. A safe... read more .)
Good sources of vitamin B6 include dried yeast, liver, other organ meats, whole-grain cereals, fish, and legumes.
Causes of Vitamin B6 Deficiency
Because vitamin B6 is present in many foods, the deficiency rarely results from inadequate intake except in severe malnutrition. However, deficiency can also occur, because extensive processing can remove vitamin B6 from foods.
Vitamin B6 deficiency often results from
Use of drugs that deplete vitamin B6 stored in the body
These drugs include antiseizure drugs Antiseizure drugs In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more , the antibiotic isoniazid (used for tuberculosis), hydralazine (used to treat high blood pressure), corticosteroids Corticosteroids: Uses and Side Effects Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more , and penicillamine (used to treat such disorders as rheumatoid arthritis and Wilson disease).
Vitamin B6 deficiency is common among people who have had a severe deficiency of protein and calories (protein-energy undernutrition Protein-Energy Undernutrition Undernutrition is a deficiency of calories or of one or more essential nutrients. Undernutrition may develop because people cannot obtain or prepare food, have a disorder that makes eating or... read more ). People with this disorder do not consume enough vitamin B6.
Symptoms of Vitamin B6 Deficiency
In adults, vitamin B6 deficiency can cause inflammation of the skin (dermatitis) and a red, greasy, scaly rash. The hands and feet may feel numb and prickling—like pins and needles. The tongue may become sore and red, and cracks may form in the corners of the mouth. People may become confused, irritable, and depressed. They may have seizures.
Rarely, vitamin B6 deficiency causes seizures in infants. Antiseizure drugs may be ineffective in treating these seizures in infants.
Because vitamin B6 is needed to form red blood cells, deficiency can cause anemia Vitamin Deficiency Anemia Vitamin deficiency anemia results from low or depleted levels of vitamin B12 or folate (folic acid). People may be weak, short of breath, and pale. Nerves may malfunction. Blood tests can detect... read more .
Diagnosis of Vitamin B6 Deficiency
History and physical examination
Response to vitamin B6 supplements
The diagnosis of vitamin B6 deficiency is based on symptoms, the presence of conditions that can cause the deficiency, and response to vitamin B6 supplements.
Blood tests may be done, but no routine blood test can clearly confirm the diagnosis.
Treatment of Vitamin B6 Deficiency
Correction of the cause
Vitamin B6 supplements
Causes of vitamin B6 deficiency are corrected when possible.
If people have the deficiency or if they are taking a drug that depletes vitamin B6 in the body, they should take vitamin B6 supplements by mouth. Taking vitamin B6 supplements usually corrects the deficiency in adults.