Inadequate intake of vitamin B-12 is much more common than previously thought. A new study in the elderly showed that 40% had low or marginal levels of B-12 considered necessary for good health. Another study showed that up to 18% of 40- and 50- year old persons had low B-12 levels. Lack of B-12 damages the nervous system resulting in loss of feeling and balance, and can also lead to dementia. The Institute of Medicine recommends that all people 50 and older take a B-12 supplement or eat vitamin B-12 fortified foods.

Source: Nutrition Action Health Letter . Jan/Feb 2006.