Vitamin B12 is necessary for the human body to function properly. It is involved in the maintaining of both red blood cells and nerve cells. It is also crucial in the synthesizing of DNA. Of the vitamins it has the most complex structure. It is also unique in having a metal ion, which is cobalt. Because our bodies generally store a few years' supply of B12, it is uncommon for a deficiency in the vitamin to occur. When there is a lack of B12 in the human body, devastating results can occur.
Functions
Vitamin B12 is one of eight B vitamins. It is water-soluble and easily absorbed into the body. It's primary role is to help maintain the healthy function of the nervous system, including the brain and to aid in the production of red blood cells. Vitamin B12 often works in conjunction with other B vitamins to achieve its objectives. For instance, B12 and B9 together work to regulate the development of red blood cells. In the case of controlling levels of homocysteine, vitamin B12 works with B6 and B9. A high level of homocysteine can contribute to heart disease, so the B vitamins are essential in regulating this amino acid.
Deficiencies
Deficiencies of vitamin B12 most often occur in the elderly. This occurs as a result of not maintaining a balanced diet or being malnourished. Others at risk for not having enough B12 are breastfed infants and pregnant women who require additional vitamins during the months they are expecting. Strict vegetarians are also candidates for vitamin B12 deficiency. People with anemia and those with liver or kidney diseases are also more likely than the general population to lack vitamin B12 in their bodies. Being deficient in the vitamin over time can cause abnormal behavior due to B12 being essential to neurological functioning. Other conditions can manifest themselves as well.
Illnesses
Many adverse conditions can develop in those who suffer a lack of vitamin B12. It is believed that a lack of B12 contributes to such illnesses as megaloblastic anemia, pernicious anemia, cardiovascular disease and stroke. A deficiency in B12 is also implicated in problems with ataxia, spastic movements, low blood pressure, dementia, psychosis, mood disturbances and Alzheimer's disease. A lack of vitamin B12 has been linked to cases of breast cancer though the connection has not been definitively proven.
Dosing
For those over 18 years of age, the RDA (recommended dietary allowance) of vitamin B12 is 2.4mcgs daily. Pregnant and lactating women have an RDA of 2.6mcgs of the vitamin. Children under the age of 18 should get 1.8mcgs or less, depending on age, with infants needing as little as 0.4mcgs. Vitamin B12-rich foods include poultry, eggs, dairy products and fish. You can also get adequate amounts of B12 through nutritional supplements.
Warning
Do not take vitamin B12 supplements if you are know to be allergic or sensitive to cobalt, cobalamin or any of the ingredients listed on the packaging. Be aware that there are possible side effects associated with B12 supplements including diarrhea, itchy rash and rosacea. Also, do not take vitamin B12 supplements if you suffer from Leber's disease, as it can contribute to a rapid worsening of the condition.
