I am not sure if vitamin B12 should be considered a vitamin. After-all, its other name is cobalamin, which is a mineral, cobalt, attached to amine (amine being a derivative of ammonia.)
Vitamin B12 is needed by every cell in the human body. A depletion of it causes high homocysteine, impaired cellular division, symptoms of anemia, cardiovascular disease, brain damage, nerve damage, and even cancer. A dead giveaway that you may have a vitamin B12 deficiency is problems with the tongue: over-sized, not healing quickly when bruised, causing difficulty in speech.
Many people are low on vitamin B12 because their chronic low stomach acid had inhibited the release of a protein produced in the stomach wall known as the intrinsic factor. This protein helps protect the vitamin from stomach acid and leads it to the terminal ileum of the small intestine, where it is picked up by another protein called transcobalamin II. From there it is transported to the blood and surrounding tissue as needed, while excess is stored in the liver for recycling.
Vitamin B12 supplements help bypass the intrinsic factor, and are currently available in many forms — methylcobalamin, adenosylcobalamin, hydroxocobalamin and cyanocobalamin — cyanocobalamin being the cheapest and most unnatural, ineffective and dangerous form. This synthetic version contains small amounts of cyanide, a dead giveaway of its foreign assimilation to the body.
Methylcobalamin also is not for everyone. Don’t be surprised if you experience strange symptoms ingesting 1000 or 2000 mcg of methylcobalamin. If you have a methylation defect, it won’t be absorbed properly, if at all.
And why so much — why thousands of mcg? The amount of vitamin B12 that your body will utilize throughout your entire life amounts to the size of ONE grain of rice! The RDA/RDI/DV only recommends about 2.4 mcg of B12. They did this for a reason. The RDA/RDI is more brilliant than we think. We in the holistic world tend to give them very little credit. B12 is the largest of B vitamins — when you consume 1000 mcg of say methylcobalamin, only 1 to 2% of it is actually absorbed. The other 98 to 99% is excreted and worse, stored in the fat cells or other tissue cells, becoming toxins. Toxins can lead to cancer. Contrary to popular belief, water-soluble vitamin does not mean all of it will be excreted from the body. Some of it will be stored just like fat soluble vitamins — in all the wrong places!
If you are taking supplemental B12, such as methylcobalamin, you must also take folate and vitamin B6 in the form of P5P. Methylcobalamin utilizes and depletes said vitamins. For this reason, it may be wise to assume that if you have a vitamin B12 deficiency, you have a deficiency of many other vitamins and minerals as well. Thus a natural multivitamin may be a wise choice to consider.
If you are having trouble absorbing methylcobalamin, the other forms such as hydroxocobalamin and adenosylcobalamin may be a consideration. Adenosylcobalamin is the form that is stored in the mitochondria and is used to fuel the cell. Hydroxocobalamin (produced by bacteria and their activities) is found naturally in food and reduces excess nitric oxide in the body. Hydroxocobalamin also converts into adenosylcobalamin and methylcobalamin.
It would be a good idea to find a supplement that contains all three forms: hydroxocobalamin, adenosylcobalamin and methylcobalamin in low dosage, for temporary use. Vitamin B12 in stored and recycled by the liver for up to five to seven years — there is no need for continual supplementation.
Natural forms of vitamin B12 include grass-fed butter, grass-fed liver and oysters.