If your B12 level is mildly low, and your MMA and homocysteine levels are high, then you may have an early or mild vitamin B12 deficiency. If only homocysteine levels are elevated (and not MMA), then you may actually have a folate deficiency. Introduction. Vitamin B12 is a water-soluble vitamin that is naturally present in some foods, added to others, and available as a dietary supplement and a prescription medication. There are no known plant sources of vitamin B12. Deficiency causes neurological disorders and megaloblastic anemia, mainly in vegans. Vitamin B 12, also known as cobalamin, is a water-soluble vitamin that is involved in the metabolism of every cell of the human body: it is a cofactor in DNA synthesis, and in both fatty acid and amino acid metabolism. It is particularly important in the normal functioning of the nervous system via its role in the synthesis of myelin, and in. B12 deficiency can cause depression, fatigue, and other serious problems. Find out more about what this vitamin does and learn how to correct a deficiency. Vitamin B12 is required for the proper function and development of the brain, nerves, blood cells, and many other parts of the body. Inherited Vitamin B12 deficiency (Imerslund-Grasbeck disease. Vitamin B12 (cobalamin) deficiency is a common cause of macrocytic anemia and has been implicated in a spectrum of neuropsychiatric disorders. The role of B12 deficiency in hyperhomocysteinemia. Since your body doesn’t make vitamin B12 Deficiency, you’ll have to get it from creature based nourishments or from supplements, and it should be devoured all the time. Vitamin B12 and folate deficiencies are a lack of these two B complex vitamins that the body needs for several important functions. They are required to make normal red blood cells (RBCs), repair tissues and cells, synthesize DNA (the genetic material in cells). Once was due to magnesium deficiency, another due to a side effect of iron supplements, and the most unusual cause of reflux - a 2cm colon polyp that was clearly almost blocking her bowel!.