Vitamin B12 is absolutely essential for human health and survival. Without vitamin B12, we can develop megaloblastic (pernicious) anemia and nervous system disorders, including dementia. We are beginning to learn that other problems, including fibromyalgia and heart disease, may be related to a deficiency of vitamin B12.
We normally get vitamin B12 in the food we eat, specifically in meat products. That includes milk and eggs. Interestingly, neither plants nor animals can synthesize vitamin B12, even though it is essential for our health. Bacteria and archaea are the only organisms that can synthesize vitamin B12. All animals must consume vitamin B12.
Here's another thing that's interesting about vitamin B12: it's a water soluble vitamin, but it doesn't just pass through our bodies and get excreted in our urine like most water soluble vitamins. We store the vitamin B12 we get from food in our liver, and reuse it over and over again.
Vitamin B12 isn't used up or converted into other substances. Vitamin B12 acts as a catalyst for chemical reactions in our bodies. Vitamin B12 is necessary for the reactions to occur, but is not changed or used up during the reaction. That's why we can store vitamin B12 and reuse it until it finally breaks down. We store about 5-6 years' worth of vitamin B12.
It would seem, then, that we would rarely see problems related to a deficiency of vitamin B12. We need minute amounts of vitamin B12 in our daily diets to replace what does get excreted, but with 5-6 years' worth in storage, that should not be a problem.
The problem occurs when people are unable to absorb enough vitamin B12 to replace what is excreted. It takes a long time for symptoms related to a deficiency of vitamin B12 to appear.
There are several situations in which absorption of vitamin B12 is minimal to absent. The most common ones are related to either lack of intrinsic factor (a substance excreted by the stomach that is necessary for vitamin B12 absorption) or malabsorption syndromes. Intrinsic factor deficiencies may be congenital or caused by various factors that affect the stomach, such as chronic gastritis, Heliobacter pylori infection, stomach stapling or other surgeries, or by the aging process. Malabsorption can happen as a result of surgery, irritable bowel syndrome or other intestinal problems.
In the past, the most reliable way for people with vitamin B12 deficiency to get supplementation was through vitamin B12 shots. Now a Vitamin B12 Patch is available. It is formulated so that vitamin B12 is absorbed directly into your bloodstream through your skin. The B12 Patch is now an easy and painless way to get vitamin B12.
