Calcium Supplements in Kids Overrated?
Children Who Get Calcium-Fortified Foods or Pills Don't Develop Stronger Bones, Study Shows
April 18, 2006 -- Most kids who take calcium supplements -- or eat
calcium-fortified foods -- don't get stronger bones, a review of clinical
The review, by Tania Winzenberg, MD, and colleagues at Australia's Menzies
Research Institute, analyzed data from 19 studies of calcium supplements in
children aged 3 to 18 years. The researchers selected only studies that tested
calcium supplements against inactive placebo and included measurements of bone
densitybone density. The time
frames of the studies were between 8.5 months and seven years.
Pooled data on all 2,859 children in the studies showed that calcium
supplements had very little, if any, effect on children's bone density.
"There is 'gold' level evidence that calcium supplements may not help to
build stronger bones in children enough to make a difference in the risk of
breaking a bone," Winzenberg and colleagues write. "The results of this
review do not support the use of calcium supplements in healthy
The findings appear in the current issue of The Cochrane Library.
It is published by the Cochrane Collaboration, an international effort to
evaluate health care research based on stringent criteria.
The studies of calcium supplements included studies of calcium pills as well
as calcium extracted from milk and added to foods.
"We found there wasn't much effect at all," Winzenberg told the
Health Behavior News Service. "It does challenge what we thought we
Kids Need Calcium
Kids' bone density is a major factor in how easily they fracture bones. But
that's small potatoes compared to the lifelong consequences of too-low bone
density. From the time people enter puberty until the time they are young
adults, they build up essentially all the bone they ever will have. Low bone
density during late childhood predicts osteoporosisosteoporosis in later life.
Childhood fracture rates are up -- a sign that kids aren't building strong
enough bones. Calcium is a main ingredient for bone building, notes calcium and
osteoporosis expert Robert Heaney, MD, professor of medicine at Creighton
University in Omaha.
"You have to have calcium or you can't store it as bone," Heaney
tells WebMD. "The human body is born with 25 grams of calcium at birth. We
have to build that up by diet. The question is how much is enough to do
The Winzenberg analysis found that calcium supplements didn't have an
effect, even in kids who were getting too little calcium in their diets. But
only three of the studies included in the analysis included kids getting less
than 500 milligrams of calcium a day.
"If a child is getting up to 600 milligrams to 800 milligrams of calcium
a day, giving more will not help," Heaney says. "So if a child is in
that range, I would predict a study would not find any improvement from calcium