To B12 or Not to B12?
Vitamin B12 supplements are everywhere and it seems medical offices offer B12 more than ever. So what is all the hype behind supplementing with vitamin B12?
To B12 or Not to B12?
Vitamin B12 in medicine is called cobalamin and is one of the eight B-vitamins the body needs. Cobalamins come in 3 forms, methylcobalamin, hydrocobalamin and cyanocobalamin. Methylcombalamin is the active bioavailable form found in nature and in the body. Hydrocobalamin is manufactured, albeit naturally by bacteria and is well know for its use as an antidote to cyanide poisoning. Hydrocobalmin can readily grab the toxic cyanide molecule and turn it into a less toxic compound that the body can handle called cyanocobalamin. Cyanocobalamin is a synthetic form and not bioavailable to the body without a few steps to change the form into a B12 the body can use such as the methyl- form. In this form a cyanide molecule is released but in such minute amounts that it is not toxic to the body but demands more steps to make B12 available for use.
B12 is not made within any organism except bacteria. Good sources of B12 would be fermented foods for beginners but it is also found in meats, eggs and milk but of course those animals also obtained it from intake of bacterial sources. Grazing animals such as cows, technically have 1 stomach but four compartments and bacteria are present in all of them, which means they are better able to absorb the B12 made directly by the bacteria in their gut. Typically bacteria in the human gut that can make B12 is distal or beyond the area in which we would normally absorb it so we cannot rely on our own intestinal bacteria to make it for us. Humans must get B12 from our food.
In order for humans to absorb B12 from our diet it must first be freed from the food we eat. This is done by the hydrochloric acid(HCl) present in our stomach. Many individuals have a decreased production of HCl, causing many issues with absorption of nutrients and B12 is one of them. Cells located in the stomach called parietal cells produce a substance called intrinsic factor(IF). B12 is such a large molecule; in fact it is the largest and structurally complicated vitamin in the body. Because it is so large it needs help with absorption across the intestinal lining. Intrinsic factor made by the parietal cells will bind with B12 so that it can be absorbed.
Once absorbed B12 is used in methylation reactions in the body. These are controlled reactions in the body that release minute amounts of energy that drive metabolism. There are trillions of methylation reactions in the body and, in controlled steps these reactions are responsible for DNA synthesis, protein synthesis, healing reactions and liver detoxification reactions, in other words they are present throughout the cell and control a multitude of important reactions in the body.
B12 belongs to a specific reaction within folate metabolism. Folate is an important substance for healthy DNA replication and cell growth. It is extremely important in pregnant women in preventing neural tube defects such as spina bifida. Within this cycle B12 assists in the conversion from homocysteine to methionine so that methionine can go on to help in protein synthesis and folate metabolism as well as energy production. This reaction is specific for the fatty acid metabolism and one-carbon metabolism, in other words breaking down the food we eat and converting it to energy, proteins and other vital reactions. Fatty acids are our fuel and when we have a deficiency of B12 as well as other compounds this process slows, resulting in physical symptoms like fatigue, irritability and cardiovascular risks. If a deficiency of B12 is severe enough it can manifest as depression because of the build-up of folate that cannot be processed further in the cycle. Many times we test the lack of vitamins by testing other compounds that get backed up in the system. For B12 it can be methylmalonic acid or folate, or even homocysteine, which is known to be associated with heart disease.
B12 and its functions were discovered in 1920 by George Whipple, he was researching for the cause of pernicious anemia. Pernicious anemia is an anemia condition and autoimmune disease caused by the body attaching the parietal cells that make intrinsic factor and bind to B12 so that the vitamin can be absorbed. As we age, our parietal cells in the stomach naturally begin to diminish and we produce less intrinsic factor to bind to B12, making it difficult to absorb and resulting in B12 deficiency. In these cases, we can bypass the stomach and patients can receive B12 injections.
There are even individuals that have a genetic mutation effecting this cycle called Methylenetetrahydrofolate reductase or MTHFR genetic defect. These individuals tend to function better on a supplement of methylated folate which skips the whole step needing the MTHF-reductase enzyme that is deficient. Its complicated as most systems are in the human body but these conditions and deficiencies can be diagnosed and treated in simple ways.
MTHFR genetic defect
B12 is also very important in the health of our red blood cells and their ability to carry the oxygen we need. A deficiency can not only produce fatigue, as stated earlier, but can also manifest in peripheral neuropathy or simply put a tingling and numbing sensation in the hands and feet.
In a recent study featured in PLOS, B12 was found to be lower in the brain in conditions such as aging, autism, and schizophrenia. In the elderly B12 levels in the brain were found to be as much as 3 times lower than healthy younger populations. Therefore, a lower level of vitamin B12 may affect age-related memory decline.
There are many vitamins, minerals and cofactors that are required for every reaction in the body. Naturopathic medicine offers specialized testing such as the micronutrient panel that measures over 35 vitamins, mineral, amino acids, metabolites and antioxidant status. Different forms of supplementation can be used as a treatment, as long as it is correctly diagnosed. It is important to speak with your naturopathic doctor about specialized testing, if needed.You can find out more information by calling Longevity Medical Health Center for a comprehensive evaluation.
Article contributed by Dr. Michelle McConnell