Study: Dietary calcium is better

ST. LOUIS – Most women know that calcium is critical in preventing osteoporosis, the disease of progressive bone loss and fractures that affects millions of Americans.

But which source is better: calcium-rich foods or supplements? A preliminary study by researchers at Washington University School of Medicine suggests dietary calcium may be better at protecting bone health.

Though not definitive, the study found that women who get most of their daily calcium from food have healthier bones and higher bone density than women whose calcium comes mainly from supplemental tablets.

That was true even though the supplement-takers had higher average levels of calcium.

Calcium from dietary sources is generally better absorbed than that from supplements, which could help explain the difference, said the study’s lead author, Dr. Reina Armamento-Villareal.

Those getting calcium from foods also had more estrogen in their bodies; the hormone is needed to maintain bone mineral density. Researchers can’t yet explain the food-estrogen connection.

The research is preliminary and offers “a springboard to do something more, a hypothesis to test,” said Armamento-Villareal, a bone specialist and assistant professor in the School of Medicine’s division of bone and mineral diseases. It was published in the May issue of the American Journal of Clinical Nutrition.

Dairy foods and calcium-fortified orange juice are excellent sources of calcium. Dark green, leafy vegetables also contain it, though it is not as readily absorbed as calcium from dairy, researchers said.

Armamento said she’d like to do a long-term study of teenagers whose bones are still developing to see what, if any, differences might emerge among young women taking calcium from diet versus supplements.