Vitamin B12 is an essential nutrient, meaning the body needs it to stay healthy and it needs to be consumed through foods because the body can’t produce it.
The human body uses vitamin B12 for many processes. These include making red blood cells (which carry oxygen throughout the body) and DNA (genetic material), producing energy, and keeping brain and nerve cells healthy.
If you don’t have enough vitamin B12 in your diet, you could develop a nutrient deficiency. Signs and symptoms of a B12 deficiency include headaches, confusion, weakness, fatigue, and anemia.
Keep reading to learn more about vitamin B12 and food sources for any diet.
What Is Vitamin B12?
Vitamin B12 is one of the water-soluble vitamins. It is also known as cobalamin. Water-soluble vitamins dissolve in water and tend to be easier for the body to absorb and use.
Normally, these vitamins aren’t stored in the body, unlike the fat-soluble vitamins, which are stored in fat tissue. However, vitamin B12 can be stored in the liver until it’s needed by cells. Even though it can be stored, without enough vitamin B12 in the diet it’s possible to develop a deficiency.
Why Is It Important?
Vitamin B12 is crucial for multiple functions in the body, including:
- Maintaining the health of nerve and brain cells
- Boosting focus and cognitive function (thinking and memory)
- Assists in making healthy red blood cells and preventing anemia
- Used to facilitate energy production
- Protects eye health
- Helps in duplicating and regulating DNA
- May help prevent congenital abnormalities (those present at birth)
Signs and Symptoms of a B12 Deficiency
Vitamin B12 deficiency is uncommon. It’s estimated to affect up to 6% of people in the United States. It’s more common for people to experience a slight depletion of B12. About 15% of people between the ages of 20 and 59 and more than 20% of people over the age of 60 have depleted levels of B12 in the U.S.
Symptoms and side effects of a B12 deficiency include:
- Poor cognitive performance
- Memory loss
- Mood changes
- Trouble concentrating
- Weakness and neurological problems
- Increased risk for neural tube defects (defects in the development of the brain, spine, or spinal cord) and cognitive delays (a child not displaying the thinking and memory abilities expected for their age)
Daily Recommended Intake
The recommended dietary allowance (RDA) for vitamin B12 is 2.4 micrograms per day. When pregnant, the RDA increases to 2.6 micrograms daily, and while breastfeeding, it’s 2.8 micrograms per day. This can be consumed through foods or dietary supplements.
No toxic effects of vitamin B12 have been identified at this time. This is likely because any excess of water-soluble vitamins can be removed from the body through urine.
Still, talk with your healthcare provider before starting any new dietary supplement. It may be beneficial to try to meet your nutrition needs through whole foods because of the variety of nutrients available in them.
Animal-Based Sources of Vitamin B12
Vitamin B12 is primarily found in animal foods and animal products. Good sources of vitamin B12 include:
Red meats like beef and pork are excellent sources of vitamin B12.
Four ounces of 80% lean ground beef provides about 2.42 micrograms of vitamin B12, which is just over 100% of the RDA for B12. Beef is also a good source of other nutrients like folate, niacin, iron, zinc, potassium, and protein.
However, red meats can be high in saturated fat. The American Heart Association recommends that people who are trying to lower their cholesterol make saturated fat less than 6% of their daily caloric intake. Try to purchase leaner cuts of red meat, which are lower in saturated fat.
Fatty fish are best known for being excellent sources of heart-healthy omega-3 fatty acids. But they’re also good sources of other vitamins, like B12. Examples of fatty fish include sardines, tuna, salmon, and trout.
Half of a filet of salmon (198 grams) provides 6.3 micrograms of vitamin B12, which is 260% of your daily needs.
The majority of the vitamins and minerals found in eggs are located within the egg yolk. A whole egg provides about 0.5 micrograms of vitamin B12, which is about 20% of the RDA.
One egg also provides 6 grams (g) of protein, 92 milligrams (mg) of potassium, 24 milligrams of calcium, 155 milligrams of choline, 90 micrograms of vitamin A, and 50 International Units (IU) of vitamin D.
Dairy products like milk, cheese, and yogurt, are good sources of several vitamins and minerals.
One 158 gram container of nonfat Greek yogurt provides 1.09 micrograms of B12 (about 50% daily need), 212 milligrams of phosphorus, 220 milligrams of potassium, 173 milligrams of calcium, and 16 grams of protein.
Shellfish, like clam, lobster, and mussels, are excellent sources of protein, vitamins, and minerals.
For example, 3 ounces of lobster provides 1.22 micrograms of vitamin B12, 16 grams of protein, 62 micrograms of selenium, 9 micrograms of folate, and 68 micrograms of choline.
Animal organ meats, like liver and kidney, are loaded with nutrients, even if they’re less popular than they used to be. Because B12 can be stored in the liver, these meats usually are the most vitamin B12-rich food.
Three ounces of beef liver provides 60 micrograms of vitamin B12, which is about 2,500% the daily recommended intake. In addition, 3 ounces of liver also provides 25 grams of protein, 5 milligrams of iron, 422 milligrams of phosphorus, 299 milligrams of potassium, 215 micrograms of folate, 26,900 International Units of vitamin A, and 42 International Units of vitamin D.
Plant-Based B12 Sources
Vitamin B12 isn’t naturally found in plant-based foods. However, some foods are fortified with vitamin B12 to help meet people’s nutritional needs, especially those following vegetarian or vegan diets.
Here are some non-animal foods fortified with vitamin B12:
Nutritional yeast is a popular food topper and cooking ingredient for vegan meal plans. It’s a species of yeast grown to be used as food and provides a savory flavor to food. However, yeast cannot make vitamin B12, so it must be fortified if it is to be used as a dietary source.
Nutritional yeast is manufactured to provide protein, vitamins, and minerals. A 16-gram serving of fortified nutritional yeast provides 24 micrograms of vitamin B12, 12 milligrams of vitamin B6, 56 milligrams of niacin, 9 milligrams of thiamin, and 8 grams of protein.
Non-dairy milk, like almond, soy, oat, or cashew milk, don’t naturally have vitamin B12. Often they are fortified to provide multiple vitamins and minerals.
For example, 8 ounces of fortified almond milk provides 3 micrograms of vitamin B12.
Grains are often fortified during processing to provide extra vitamins and minerals, such as folic acid and vitamin B12.
In one and a half cups of fortified ready-to-eat cereal, there is about 1.5 micrograms of vitamin B12.
Vitamin B12 is an important nutrient for health and wellbeing. It helps with energy, red blood cells, nerve cells, and DNA production. Without adequate vitamin B12 in the diet, you could develop a deficiency and experience symptoms like fatigue, weakness, headaches, and poor concentration.
Vitamin B12 is naturally found in animal foods like red meat, liver, eggs, fish, and dairy products. It’s also found in fortified plant-based foods like nutritional yeast and fortified non-dairy milk and grains.
A Word From Verywell
Vitamin B12 is a key nutrient for your body to function. It’s available in a wide variety of foods. If you’re concerned you aren’t getting enough vitamin B12 or believe you have a deficiency, talk with your healthcare provider.
Frequently Asked Questions
What is the difference between water-soluble and fat-soluble vitamins?
Water-soluble vitamins, like vitamin C and B complex vitamins, dissolve in water, usually aren’t stored in the body, and any excess is removed from the body by the kidneys.
Fat-soluble vitamins, vitamins A, E, D, and K, can only be absorbed when consumed with fat, and they are stored within body fat until needed.
Does vitamin B12 only come from animals?
Naturally occurring vitamin B12 is only found in animal products, like meat, eggs, or dairy. However, to meet the needs of people following plant-based diets and vegan diets, vitamin B12 is added to some non-animal products like fortified nutritional yeast, fortified non-dairy milk, and fortified grains.
How do you know if you need a B12 supplement?
If you have the symptoms of a B12 deficiency, you may need a supplement. Talk with your doctor if you have symptoms like trouble concentrating, fatigue, weakness, headaches, or depression symptoms. It is important to have these symptoms properly diagnosed and not assume they are due to a deficiency, as they could have many different causes.