Vitamin B-12, also known as cobalamin is water-soluble and plays a key role in red blood cells production, DNA synthesis, metabolism and maintenance of healthy nervous system. Vitamin B-12 also works together with folic acid and vitamin B-6 to lower high levels of homocysteine. High levels of homocysteine can cause cardiovascular disease. Strict vegetarians and older adults are at high risk for B-12 deficiency.
Neurological Symptoms
The body needs vitamin B-12 for proper neurological functioning. Patients with low levels of B-12 cause neurological symptoms such as weakness, fatigue, numbness and tingling in hands and feet, difficulty maintaining balance, memory loss, depression, irritability, personality changes, and confusion. Severe B-12 deficiency can lead to permanent neurological symptoms such as severe dementia, psychosis and movement problems in adults and children, according to the Office of Dietary Supplements.
Hematological Symptoms
Vitamin B-12 is absorbed in the stomach and intestines with the help of a stomach protein known as intrinsic factor. Lack of intrinsic factor leads to pernicious anemia or megaloblastic anemia, according to the Mayo Clinic. Symptoms of pernicious anemia include fatigue, increased heart rate, shortness of breath, pale skin, weak muscles, numbness of extremities, decreased appetite, irritability, problems walking and weight loss.
Sources of Vitamin B-12
The daily dietary requirement of vitamin B-12 is 2.4 mcg in adults, according to MedlinePlus. Vitamin B-12 is mainly found in animal products such as beef liver, red meat, salmon, clams, shellfish, poultry, eggs, tuna, ham, milk, yogurt, cheese, trout and haddock. Vitamin B-12 is also added to fortified breads and cereals. Older adults and strict vegetarians may require vitamin B-12 supplements. Older adults have a hard time absorbing vitamin B-12 due to age-related changes in the digestive tract.
Gastrointestinal Symptoms
Vitamin B-12 deficiency may cause stomach inflammation leading to gastrointestinal symptoms such as loss of appetite, nausea, vomiting, diarrhea, constipation, soreness of the mouth and tongue, weight loss, and failure to thrive and developmental delays in children, according to the Office of Dietary Supplements. Children who experience failure to thrive have a rate of weight gain that is significantly below that of other children of similar age and sex.
