Vitamin B12 is vital to brain health and energy. It is also essential for building new blood cells, DNA, and nerve insulation. Deficiencies lead to brain fog and fatigue. Studies show that it may help with weight loss, chronic fatigue, MS, nerve damage, brain disorders, shingles, and headaches.
Since your body doesn't make vitamin B12, you have to get it from animal-based foods or from supplements on a regular basis. While B12 is stored in the liver for up to five years, you can eventually become deficient if your diet doesn't help maintain the proper levels.
How Much to Get?
The answer depends on things including your age, your eating habits and medical conditions, and what medications you take.
Food Sources of Vitamin B12
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.
Vitamin B12 Deficiency
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, or if you drink heavily.
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
Alcohol misuse or heavy drinking can make it harder for your body to absorb nutrients or prevent you from eating enough calories. One sign that you lack enough B12 may be glossitis, or a swollen, inflamed tongue.
Been taking certain medications that interfere with the absorption of B12. This includes some heartburn medicines including proton pump inhibitors (PPIs) such as esomeprazole (Nexium), lansoprazole (Prevacid), omeprazole (Prilosec OTC), pantoprazole (Protonix), and rabeprazole (Aciphex), H2 Blockers such as cimetidine (Tagamet) and famotidine (Pepcid AC); and certain diabetes medicines such as metformin (Glucophage).
You can also get vitamin B12 deficiency if you follow a vegan diet 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.
Symptoms of Vitamin B12 Deficiency
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
A smooth tongue
Constipation, diarrhea, loss of appetite, or gas
Nerve problems like numbness or tingling, muscle weakness, and problems walking
Mental problems like depression, memory loss, or behavioral changes
If you have pernicious anemia or have trouble absorbing vitamin B12, you'll need to supplement your B12 levels with a shot or through an IV.
For most people, treatment resolves the problem. However, any nerve damage that happened due to the deficiency could be permanent.