October 01, 2021

Vitamin B-12

A little bit of this nutrient can have a big impact on health

Vitamin B-12 is an essential nutrient for your body — it supports the health of nerve and blood cells and contributes to the production of DNA. Typically, an adult needs 2.4 micrograms of vitamin B-12 a day, which can be obtained with just 3 ounces of cooked ground beef or 3 ounces of Atlantic salmon. Vitamin B-12 is stored in the liver until it is needed by the body.

Vitamin B-12 is found naturally in animal products including eggs, meat, poultry, fish, shellfish, milk, cheese and yogurt. Foods such as nutritional yeast and breakfast cereal are sometimes fortified with vitamin B-12.

Despite the availability of vitamin B-12 in some foods, it's not always easy for everyone to get adequate amounts of this essential nutrient. Older adults, as well as people with certain medical conditions and dietary restrictions, are at risk of vitamin B-12 deficiency.

The details on deficiency

There are two main causes of vitamin B-12 deficiency. One is inadequate intake. This is rare and tends to be limited to people who eat a vegetarian or vegan diet, which avoids animal products. It can usually be managed with consumption of fortified foods or a dietary supplement.

The other is insufficient absorption. You may be consuming what seems like enough vitamin B-12 from food sources, but your body isn't taking it in properly. People over age 50 can be at increased risk of vitamin B-12 deficiency because they don't have enough stomach acid to adequately absorb it. In this case, the increased concentration of vitamin B-12...