Vitamin B12 Deficiency Widespread
August 27, 2000
Almost 40% of the U.S. population is deficient in
vitamin B12 according to a recent study from Tufts University in Boston
and a vast majority of them are completely unaware.
Researchers looked at 3,000 men and women participating
in the ongoing Framingham Offspring Study
They found 39 percent with plasma B12 levels in
the "low normal" range - below 258 picomoles per liter (pmol/L).
Although the currently accepted deficiency level
is 148 pmol/L, some people exhibit neurological symptoms at significantly
higher levels, said study leader Katherine Tucker, a nutritional epidemiologist.
Nearly 9 percent of the study population fell
below the current deficiency level, although the researchers admit
that there is a question as to what the proper cutoff value for deficiency
A deficiency of vitamin B12 (cobalamin) deficiency
can cause pernicious anemia, which is marked by fewer but larger red blood
cells. Deficiencies can cause walking and balance disturbances, a loss
of vibration sensation, confusion, and even dementia.
The study covered people from 26 to 83 years old,
and was funded by the Agricultural Research Service (ARS), USDA's
chief scientific agency.
Probably the most surprising result by far was
that the youngest group (26 to 49 years old) had about the same B12
status as the oldest group (65 and up).
- The use of B12 supplements use dropped the percentage
of people with plasma B12 below 185 pmol/L -- from 20% to 8%.
Since the body requires B12 to make the protective
coating surrounding the nerves, inadequate B12 can result in nerve damage
Jean Mayer USDA Human Nutrition
Research on Aging at Tufts University, Boston, Mass.