B12 is a powerhouse, and is called the energy vitamin. It helps make DNA, nerve and blood cells, and is crucial for a healthy brain and immune system. Your metabolism does not run smoothly without it.
But B12 isn’t like other vitamins. It’s only found in animal products like eggs, meat, shellfish, and dairy. Up to 15% of people don’t get enough B12. They’re more likely to be vegetarians, have celiac disease, or other digestion problems, or be an adult over 50.
The signs of vitamin B12 deficiency include exhaustion, rapid heartbeat, and brain fog.
Vitamin B12 does a lot of things for your body. It helps make your DNA and your red blood cells, for example.
Since your body doesn’t make vitamin B12, you have to get it from animal-based foods or from supplements. And you should do that on a regular basis, because your body doesn’t store vitamin B12 for a long time.
The average recommended amounts, measured in micrograms (mcg), vary by age:
- Infants up to age 6 months: 0.4 mcg
- Babies age 7-12 months: 0.5 mcg
- Children age 1-3 years: 0.9 mcg
- Kids age 4-8 years: 1.2 mcg
- Children age 9-13 years: 1.8 mcg
- Teens age 14-18: 2.4 mcg (2.6 mcg per day if pregnant and 2.8 mcg per day if breastfeeding)
- Adults: 2.4 mcg (2.6 mcg per day if pregnant and 2.8 mcg per day if breastfeeding)
B12: Food Sources
You can get vitamin B12 in animal foods, which have it naturally, or from items that have been fortified with it.
Animal sources include dairy products, eggs, fish, meat, and poultry. If you’re looking for a food fortified with B12, check the product’s Nutrition Facts label.
B12: What Causes Deficiency
Most people in the U.S. get enough of this nutrient. If you’re not sure, you can ask your doctor if you should get a blood test to check your vitamin B12 level.
With age, it can become harder to absorb this vitamin. It can also happen if you have had weight loss surgery or another operation that removed part of your stomach, if you drink heavily, or if you’ve taken acid-reducing medications for a long time.
You may also be more likely to develop vitamin B12 deficiency if you have:
- Atrophic gastritis, in which your stomach lining has thinned
- Pernicious anemia, which makes it hard for your body to absorb vitamin B12
- Conditions that affect your small intestine, such as Crohn’s disease, celiac disease, bacterial growth, or a parasite
- Immune system disorders, such as Graves’ disease or lupus
You can also get vitamin B12 deficiency if you follow a vegan diet (meaning you don’t eat any animal products, including meat, milk, cheese, and eggs) or you are a vegetarian who doesn’t eat enough eggs or dairy products to meet your vitamin B12 needs. In both of those cases, you can add fortified foods to your diet or take supplements to meet this need.
B12: Deficiency Symptoms
If you have vitamin B12 deficiency, you could become anemic. A mild deficiency may cause no symptoms. But if untreated, it may lead to symptoms such as:
- Weakness, tiredness, or lightheadedness
- Heart palpitations and shortness of breath
- Pale skin
- A smooth tongue
- Constipation, diarrhea, loss of appetite, or gas
- Nerve problems like numbness or tingling, muscle weakness, and problems walking
- Vision loss
- Mental problems like depression, memory loss, or behavioral changes
B12: Treating Deficiency
If you have pernicious anemia or have trouble absorbing vitamin B12, you’ll need shots of this vitamin at first. You may need to keep getting these shots, take high doses of a supplement, or get it nasally after that.
If you don’t eat animal products, you have options. You can change your diet to include vitamin B12-fortified grains, a supplement or B12 injections, or a high-dose oral vitamin B12 if you are deficient.
Older adults who have a deficiency should take a daily supplement or a multivitamin that contains B12.
For most people, treatment resolves the problem. But, keep in mind that any nerve damage that happened due to the deficiency could be permanent.
B12: Preventing Deficiency
Most people can prevent vitamin deficiency by eating enough meat, poultry, seafood, dairy products, and eggs.
If you don’t eat animal products, or you have a medical condition that limits how well your body absorbs nutrients, you can take a multivitamin or other supplement and fortified foods.
If you choose to take supplements, check and find out if they clash with any current medications you’re taking.