Vitamin B12 deficiency can be sneaky, harmful

POSTED JANUARY 10, 2013, 10:03 AM , UPDATED OCTOBER 18, 2016, 2:21 PM

Patrick J. Skerrett, Former Executive Editor, Harvard Health

What harm can having too little of a vitamin do? A severe vitamin B12 deficiency can lead to deep depression, paranoia and delusions, memory loss, incontinence, loss of taste and smell, and more. The human body needs vitamin B12 to make red blood cells, nerves, and DNA, and to carry out other functions. The average adult should get 2.4 micrograms a day. Like most vitamins, B12 can't be made by the body. Instead, it must be gotten from food or supplements. And therein lies the problem: Some people don't consume enough vitamin B12 to meet their needs, while others can't absorb enough, no matter how much they take in. As a result, vitamin B12 deficiency is relatively common, especially among older people.
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