Common food sources of vitamin B12 include beef, tuna, salmon, snapper, pork, eggs, milk, cottage cheese and yogurt.Vitamin B12 is essential for good health. It helps all your cells work normally and is especially important for building healthy red blood cells and creating and preserving a healthy nervous system.

Aging and a number of other conditions increase the risk of vitamin B12 deficiency. You may be at risk if you are over 65, as 10 to 30 per cent of older adults do not absorb the vitamin B12 found naturally in foods very well. You could also be at risk if you follow a vegan or vegetarian diet, have Crohn's disease or diabetes, or take medications that reduce your stomach acid.

Pregnant and breastfeeding women should also take care to meet their Vitamin B12 needs, because this vitamin is important for your child's healthy early development.

A vitamin B12 deficiency can lead to a type of anemia that can make you feel tired. Other common symptoms include memory problems, loss of balance or tingling in fingers and/or toes. Low vitamin B12 intakes or the body's decreased ability to use B12 may even contribute to increased bone fractures and fragility.