Vitamin B12 is an essential nutrient your body requires to produce your red blood cells and promote a healthy nervous system. It cannot be made by our bodies, so we can get it from outside sources where it does naturally occur, such as meat, fish, poultry, eggs, and/or dairy. Some other foods, such as bread or milk, can also be found fortified with B12. Deficiencies are very common, particularly in the elderly, vegans, those who have had weight loss surgery which affects absorption of this vitamin and others, and those who take antacids very frequently. For this reason, make sure to note these signs and symptoms so you can identify a deficiency with your primary care physician and ensure you achieve optimal health.