Vitamin B12, sometimes also called Cyanocobalamin, is a water-soluble vitamin that benefits your mood, energy level, memory, heart, skin, hair, digestion and more. Vitamin B12 is also an essential vitamin for addressing adrenal fatigue, multiple metabolic functions — including enzyme production, DNA synthesis and hormonal balance — and maintaining healthy nervous and cardiovascular systems. It also benefits the central nervous system in many important ways: It helps maintain the health of nerve cells — including those needed for neurotransmitter signaling — and helps form the protective covering of nerves, called the cell’s myelin sheath. Compared to other vitamins, we don’t need a very large amount of vitamin B12, According to the NIH, the Recommended Dietary Allowance (RDA) for vitamin B12 is 0.4 mcg for Infants of 0–6 months: 0.4, 0.5 mcg for Infants of 7–12 months, 0.9 mcg for toddlers aged between 1 and 3 years, 1.2 mcg for children aged between 4 and 8 years: 1.8 mcg for children aged between 9 and 13 years. Adult men and women over age 14 should have 2.4 micrograms while pregnant women are advised to take 2.6 micrograms and breastfeeding women 2.8micrograms. When vitamin B12 levels are low, almost every cognitive function can suffer. A vitamin B12 deficiency can, thus, show up in many different negative symptoms, many of which are very noticeable, such as potential chronic fatigue, mood disorders like depression, chronic stress , muscle aches and weakness, joint pain, shortness of breath and breathing difficulty, dizziness, poor memory, inability to concentrate well, abnormal heart problems, such as palpitations, poor dental health, digestive problems like nausea, diarrhea or cramping, or a poor appetite. A more serious deficiency can also cause a form of anemia called pernicious anemia, a serious condition that can cause memory loss, confusion and even long-term dementia. Vitamin B-12 is generally considered to be safe, and no "Upper Tolerable Intake Level" has been established.