B complex vitamins are nutrients that the body needs in small amounts (micronutrients) for metabolism, energy production, and overall health of cells, skin, bones, muscles, and the nervous system. The B Complex Vitamin Profile measures all B vitamins in the blood in order to objectively assess a person's nutritional status.
The B vitamins tested are: B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), B12 (cyanocobalamin).
B complex vitamins are absorbed from food, used according to the body's needs and their excess is eliminated through urine. Because B vitamins are water-soluble, only small amounts can be stored in the body and should be taken on a regular basis from foods rich in B vitamins or supplements.
Who should test for B complex vitamins?
Patients with symptoms, signs, and laboratory findings that indicate a deficiency in a B complex vitamin
- Nervous system disorders (hallucinations, numbness, irritability, dementia, amnesia)
- Disorders of the skin and mucous membranes
- Increased Homocysteine
Patients at risk for B vitamin deficiency
- Gastrointestinal surgeries
- Celiac disease
- Inflammatory bowel diseases (Crohn's disease and ulcerative colitis)
Vitamin B deficiencies can occur when:
- There is an insufficient supply of B vitamins through food
- There is a problem in the absorption of vitamins from the gastrointestinal tract
- There is an inability to use one or more of the vitamins
- Foods that inhibit the action of vitamins are consumed
- Deficiency of another vitamin or trace element prevents their use
- The need for vitamins is increasing
Deficiencies of B complex vitamins are more common in people with malnutrition and a bad diet, in chronic alcoholism, in people with malabsorption or other digestive disorders, celiac disease, inflammatory bowel diseases, and the elderly. They are also sometimes seen in other chronic diseases, such as cancer and after cancer chemotherapy, in peculiar diets, and in prolonged diarrhea. Pregnant women with poor nutrition are at increased risk for B complex vitamin deficiencies as well as their babies. Rarely, there may be inherited metabolic diseases that prevent the use of certain B vitamins.
Symptoms associated with B complex vitamin deficiency may be characteristic in specific and severe deficiencies, but may also be nonspecific, especially in cases of mild to moderate deficiency. Because multiple deficiencies of B complex vitamins or other vitamins usually coexist, there may also be multiple symptoms. The most common symptoms of B complex vitamin deficiencies include skin rashes or dermatitis, inflammation of the tongue, numbness, tingling or hallucinations in the hands or feet, anemia, fatigue, and mood disorders.
Toxicity from B complex vitamins occurs rarely and usually when excessive amounts of supplements are taken. High concentrations of certain B complex vitamins can affect the liver or nervous system.