These are notes from The Encyclopedia of Healing Foods by Michael Murray that I use to keep some nutritional information fresh in my mind
B12 is vital in nerve signaling, DNA synthesis, and is responsible for activating folic acid to help in those processes. Thus, a deficiency in B12 will lead to a deficiency in folic acid. Because of its’ role in nerve functioning and brain health, a deficiency in B12 can mimic Alzheimer’s in the elderly.
Although B12 is widely recognized as being only available in animal products (liver, fish, eggs, meat, cheese), it has been noted that fermented foods and nutritional yeast contain B12. However, there is some evidence that the form of B12 in those foods is not the form our bodies require. Supplementing B12 is a good option for those who don’t eat animal products.
As previously mentioned, folic acid works with B12 in many processes including DNA synthesis and especially cellular division. A deficiency in folic acid affects the rapidly dividing cells such as red blood cells and those of the GI tract.
Folic acid, B12 and betaine also reduce body concentrations of homocysteine. Homocysteine plays a role in the conversion of amino acids, however elevated levels of homocysteine promote atherosclerosis by damaging the arteries and osteoporosis by interfering with collagen formation in bones.