Vitamin C May Help Old Men Maintain Stronger Bones,
Did not see significant effects of vitamin C intake
on bone in old women
By Rosalie Marion
8, 2008 - Findings from a new study suggest vitamin C may be protective
against bone loss in older men. Researchers funded by the Agricultural
Research Service (ARS) reported the findings in the October issue of the
Journal of Nutrition.
The study was led by epidemiologist Katherine
Tucker with the Jean Mayer USDA Human Nutrition Research Center on Aging
(HNRCA) at Tufts University in Boston, Mass. Tucker directs the HNRCA's
Dietary Assessment and Epidemiology Research Program.
Osteoporosis - a condition in which bones become
porous and weak - affects about 10 million people in the U.S.
population, and low bone mass is a public health concern among another
44 million older people aged 50 and older.
The researchers wanted to examine whether fruit-
and vegetable-specific antioxidants such as vitamin C might decrease
oxidative stress that is linked to accelerated bone loss.
In the Framingham Osteoporosis Study, bone mineral
density at the hip, spine and forearm was measured in 344 men and 540
women aged 75 on average.
Because people at risk for bone loss, such as
smokers, may use vitamin C supplements more often, the potential effects
of vitamin C intake obtained from diet, supplements, and both diet and
supplements were examined.
Interactions based on smoking, calcium and vitamin
E intakes were tracked.
The researchers observed significant positive
associations for total vitamin C - both dietary and supplemental - among
men who never smoked.
Among a subset of the participants—whose bone
mineral density was again measured after four years—different
interactions were observed.
During those four years, total vitamin C appeared
to be protective against losses in bone mineral density in two areas of
the hip among men with low calcium or vitamin E intakes.
That finding is consistent with previous reports by
Tucker and other researchers that higher fruit and vegetable intake has
positive effects on bone mineral status.
The researchers did not observe significant effects
of vitamin C intake on bone in women.
The best food sources of vitamin C are citrus
fruits, berries, melons, tomatoes, potatoes, green peppers and leafy
green vegetables. Vitamin C is sensitive to air, heat and water, so it
can easily be destroyed by prolonged storage, overcooking and processing