Drinking a lot of milk as a child may help prevent the damaging effects of bone deterioration in old age, a University of Pittsburgh study has found.

Of 255 women between 49 and 66, those who drank the most milk as children had the densest bones as adults, Rivka Black Sandler writes in the American Journal of Clinical Nutrition.

White women are most at risk of osteoporosis, the loss of bone mass in old age, and often suffer spontaneous, life-threatening fractures in old age. Men and black women start with more bone mass and do not become as frail when they lose some of that bone mass later in life.

Milk and other sources of calcium at an early age, Sandler and her colleagues write, can help build up bone mass to "an optimal peak." Other calcium sources include cheese, yogurt, spinach, kale and broccoli.

Sandler determined bone mass by measuring a bone in the arm.

A Purdue University nutritionist, meanwhile, warns that taking antacids as calcium supplements can cause problems.

"Long-term use of antacids can actually stimulate the stomach to produce more acid, aggravating stomach problems," says April Mason in a newsletter from the university. "Many antacids also contain aluminum compounds that . . . can contribute to calcium loss by increasing calcium excretion."