Foods high in Vitamin B-12

Why Vitamin B-12 matters

Vitamin B12 (cobalamin) is a water-soluble vitamin that your body uses to produce red blood cells, synthesize DNA, and maintain the myelin sheath that insulates nerves. Unlike most vitamins, it is made exclusively by bacteria — animals accumulate it through their gut microbes or diet, which is why natural food sources are almost entirely animal-based: clams, liver, sardines, mackerel, beef, eggs, and dairy. Plant foods contain no reliable B12 unless fortified (nutritional yeast, plant milks, breakfast cereals). Adults need 2.4 µg per day, and absorption depends on intrinsic factor — a protein made in the stomach — so people on acid-reducing medications or with atrophic gastritis absorb poorly even when intake is adequate.

Daily intake reference

Signs of low intake

B12 deficiency develops slowly because the liver stores a 3 to 5 year supply, but once depleted it causes megaloblastic anemia (fatigue, breathlessness, pale skin) and neurological damage that can become permanent if untreated. Early signs include tingling or numbness in hands and feet, balance problems, memory loss, brain fog, glossitis (a smooth inflamed tongue), and depression. Vegans, vegetarians of more than five years, adults over 50, and people taking metformin or proton pump inhibitors long-term are at highest risk and should consider routine serum B12 or methylmalonic acid testing.

Best for these diets

B12 is abundant in animal foods and fortified plant products:

• High-protein
• Keto
• Paleo
• mediterranean