Vitamin B-complex consists of eight different B vitamins: thiamine or B1, riboflavin or B2, niacin or B3, pantothenic acid or B5, pyridoxine or B6, biotin or B7, folate or B9, and cobalamin or B12. The symptoms of a vitamin B complex deficiency are manifested differently depending on which specific component the body is lacking.
A deficiency of thiamine (vitamin B1) is called beriberi and occurs rarely in the U.S. Thiamine is primarily involved in muscle and nerve function. Per the University of Maryland Medical Center, when the body is not getting enough thiamine, symptoms of a vitamin B deficiency include: swelling or tingling in the hands and feet, difficulty walking and breathing, and numbness.
Riboflavin (vitamin B2) plays a role in the production of energy and cellular function. When the body is lacking in riboflavin, the deficiency is called ariboflavinosis, according to the Linus Pauling Institute at Oregon State University. Among the symptoms of a vitamin B2 deficiency are a sore throat, dry cracked lips, and a swollen or irritated tongue.
A deficiency of niacin (vitamin B3) is scientifically known as pellagra. Because niacin plays a role in skin health, a deficiency of niacin often causes skin problems. When the body is lacking in niacin, the symptoms of a vitamin B complex deficiency include skin rashes or very dry skin, diarrhea, and neurological impairment.
Pantothenic acid (vitamin B5) is crucial to the production of energy and metabolism of various nutrients. The Linus Pauling Institute reports that a deficiency of pantothenic acid is incredibly rare, occurring only as a result of extreme malnutrition. A mild deficiency may cause symptoms of fatigue.
A deficiency of pyridoxine (vitamin B6) is associated with alcoholism, and some medications.
In mild cases, symptoms of a vitamin B6 deficiency include sores on the tongue, irritability, and depression, per the National Institutes of Health. Vitamin B6 plays a role in neurological function so when the body experiences a severe deficiency, seizures and other neurological problems develop.
Biotin (vitamin B7) plays a role in the nervous system, the skin, and digestive health. A deficiency of biotin in rare, though it can occur as a result of eating raw egg whites for an extended period of time, per the Linus Pauling Institute. Symptoms of a vitamin B deficiency of biotin can include abnormally low blood sugar, hair loss, and skin rashes.
Folate (vitamin B9) is involved in the production of proteins and blood cells, per the National Institutes of Health. Symptoms of a vitamin B deficiency of folate include blood anemia. This anemia can eventually cause fatigue and lack of energy.
Cobalamin (vitamin B12) deficiency can also cause anemia. The Harvard School of Public Health reports that a vitamin B12 deficiency can cause mental problems such as memory loss and confusion. According to the UK’s National Health Service, symptoms of a vitamin B12 deficiency can also include frequent oral ulcers.
The symptoms of a vitamin B-complex deficiency largely depend on which specific vitamin is lacking in the body. Many of the B vitamins are responsible for functions of the nervous system, digestive system, and skin health, and symptoms of a deficiency manifest themselves in these systems. Any questions about the symptoms of vitamin B-complex deficiency should be directed to an individual’s doctor.
