Vitamin B12 is an essential nutrient that plays a vital role in the production and maintenance of cells within the body. Despite being essential, the human body cannot produce this nutrient and it does not carry the bacteria that do produce it. The natural source of this nutrient is animal products such as meat (especially liver), sea food (especially shell fish), eggs, and dairy products. Today the nutrient is also added to many breads and cereals as part of the nutritional fortification process. Nevertheless, Vitamin B12 deficiencies are not particularly uncommon, especially among at risk groups: vegans and/or strict vegetarians), people over the age of fifty, people with assorted gastrointestinal disorders, and those with other medical conditions (pregnancy, hyperthyroidism, AIDS, alcoholism, and so on). These individuals very often decide to get a B12 shot.
A deficiency usually begins gradually with elevated homocysteine levels, which do not pose a threat to younger people, but can be a leading indicator of serious cardiovascular problems in older people. The earliest noticeable symptoms include digestive problems, lack of appetite, nausea and unusual fatigue. The problem with these symptoms is that they may be attributable to many different causes, so people at risk of a vitamin B12 deficiency should pay special attention. Women get a more alarming early warning signal: a loss of menstruation; which should be enough to alert her that something is wrong.
More advanced physical symptoms of a Vitamin B12 deficiency include: diarrhea; erectile disorder (in men); fever; frequent upper respiratory infections; hyperactive reflexes; increased bleeding; infertility (in women); macrocytic anemia; nervousness; numbness; sore tongue; and tingling of the hands and feet. Once a deficiency gets bad enough there are also usually mental symptoms as well such as: impaired memory, mild depression; paranoia; and significant behavioral changes.
Worst of all though are the neurological symptoms, most of which are described as subacute combined degeneration (SCD). The physical symptoms include: assorted mental problems (apathy, confusion, dementia, depression, irritability); impaired movement (awkward, clumsy, or stiff); impaired vision; insomnia; loss of balance; physical weakness; speech impairment (not common); unusual sensations (tingling, numbness). The real problem with SCD is that if it is not detected and treated quickly enough, it can result in permanent damage. Therefore the neurological aspect of a Vitamin B12 deficiency is usually considered the primary concern as the other symptoms are easily reversible. Regardless, getting supplemental B vitamin shots can be the solution.
