RDA: 2 mcg (Children 1.5 mcg; Adults 2 mcg; Pregnancy 3 mcg; Lactating 2.5 mcg)

Roles of vitamin B12 in the body

• Essential for regeneration of red blood cells
• Helps make DNA and hemoglobin
• Maintains nerve health and mental abilities

Deficiency: Vitamin B12 deficiency causes Pernicious anemia; symptoms of the disease include fatigue, pale yellow skin, anorexia, weight loss, apathy and depression. Glossitis (smooth red tongue) is also a symptom of vitamin B12 deficiency.

Correction of marginal deficiencies may have speed up recovery from illness or surgery and alleviate symptoms due to neurological damage or deterioration of mental functioning. (B12 deficiency is sometimes misdiagnosed as Alzheimer's.)

Vitamin B12 deficiency is more common in elderly people, breast-fed babies of vegan mothers, and vegans. It may not show up for some time because the body can store sufficient B12 for two to three years.

Toxicity: No evidence of toxicity.

Good food sources of vitamin B12: Vitamin B12 is present in meat, liver, eggs, dairy products, fish and soy drinks. There are negligible amounts in vegetables, grains, brewer's yeast, soy products (tofu, miso, tempeh and tamari). Cooking does not usually diminish vitamin B12 content, although alcohol can interfere with B12 absorption.