Vitamin B12 is the largest and most complex of all the vitamins. It is unique among vitamins in that it contains a metal ion, cobalt. For this reason cobalamin is the term used to refer to compounds having B-12 activity. Methylcobalamin and 5-deoxyadenosyl cobalamin are the forms of vitamin B-12 used in the human body. The form of cobalamin used in most supplements, cyanocobalamin, is readily converted to 5-deoxyadenosyl and methylcobalamin.
Cobalamin is known to keep your red blood cells healthy. If you eat enough cobalamin, and if your body can use it properly, you make millions of nice round, healthy red blood cells every day. If you don't eat enough, or you can't use it properly, you can't make enough red blood cells, and the ones you do make are too large and fragile to work well. When you don't have enough red blood cells to carry oxygen and nutrients around your body, you develop anemia.
All your cells, not just your red blood cells, need cobalamin to grow and divide properly. For example, you need it to make all the different cells in your immune system, including white blood cells.
Cobalamin's next big role is in making the protective fatty layer, or sheath, that coats your nerve cells - sort of like insulation on electric wires. If the sheath is damaged because you don't have enough vitamin b12 cobalamin, you start getting the equivalent of static on the line. Really bad static can interfere with your mental function - so much that people think you're senile.
Cobalamin is a team player. Working with the other B vitamins, but especially with pyridoxine and folic acid, it helps you turn the carbs, fats, and proteins in your food into energy in your cells.
Generally, vitamin B12 side effects are quite rare; however there are reported cases of allergic reactions to vitamin b12 injections, but it is unknown if these allergic reactions are due to the vitamin b12 itself or the preservatives in the injectable vitamin b12. (Most vitamin b12 injections contain some preservatives).
Side Effects of Vitamin B12 can include:
Anxieties and panic attacks
Skin rash, hives, or itchy or swollen skin
Vitamin B 12 Benefit
Cobalamin and Cancer - Folate is required for synthesis of DNA and there is evidence that decreased availability of folate results in strands of DNA that are more susceptible to damage. Deficiency of vitamin B 12 traps folate in a form that is unusable by the body for DNA synthesis. Both vitamin B 12 and folate deficiencies result in a diminished capacity for methylation reactions.
Thus, vitamin B 12 deficiency may lead to an elevated rate of DNA damage and altered methylation of DNA, both of which are important risk factors for cancer. A recent series of studies in young adults and older men indicated that increased levels of homocysteine and decreased levels of vitamin B 12 in the blood were associated with a biomarker of chromosome breakage in white blood cells. In a double-blind placebo- controlled study the same biomarker of choromosome breakage was minimized in young adults who were supplemented with 700 mcg of folic acid and 7 mcg of vitamin B-12 daily in cereal for two months.
Vitamin B 12 Cobalamin and Depression -
Observational studies have found as many as 30% of patients hospitalized for depression to be deficient in vitamin B-12. A recent cross-sectional study of 700 community-living physically disabled women over the age of 65 found that vitamin B-12 deficient individuals were twice as likely to be severely depressed as non-deficient individuals. The reasons for the relationship between vitamin B 12 deficiency and depression are not clear.
Vitamin B 12 and folate are required for the synthesis of S-adenosylmethionine, a methyl group donor essential for the metabolism of neurotransmitters, whose bio availability has been related to depression. Because few studies have examined the relationship of vitamin B-12 status and the development of depression over time, it cannot yet be determined if vitamin B 12 deficiency plays a causal role in depression. However, due to the high prevalence of vitamin B-12 deficiency in older individuals, it may be beneficial to screen them for vitamin B 12 deficiency as part of a medical evaluation for depression.