Bone density is like a savings account – if you don’t put in, you’ll be broke.

Between the ages of 13 and 35, people are able to make deposits toward healthy bones, said Angie Ha, assistant professor of nutrition. These deposits include protein, calcium and vitamin D.

“You make deposits when you’re young so then, when you’re older and a rainy day comes along, your body is able to withdraw,” she said.

Bone density is literally the thickness of the bone cortex, which is the structural part of the bone, said chief university physician Dr. Ray Leone.

No bones about it

Ha said the “most critical” time to increase bone density is between the ages of 13 and 18. That’s when the body reaches peak density, about 90 percent to 95 percent of its total bone density.

A person’s bones can continue to get stronger until somewhere between ages 30 and 35, said Natalie Caine-Bish, assistant professor of nutrition. After that, people either maintain or lose bone density.

She said testosterone and estrogen, the sex hormones, protect people’s bones.

Once women go through menopause, their estrogen levels drop and without estrogen, bone density will “decline pretty sharply,” Ha said.

Because men don’t usually see a drop in their testosterone until after most women reach menopause, they may not see the effects of osteoporosis until they are 80 or 90 years old, Caine-Bish said.

If a person has osteoporosis, they may fracture a bone due to low density. “Osteopenia” is a level above osteoporosis, but still indicates a modest fracture risk.

College-aged students can try to avoid osteoporosis or osteopenia, by gaining 5 to 10 percent of their maximum bone density through minimal weight-bearing exercise and by getting enough calcium and vitamin D, Leone said.

“It’s inevitable you will lose bone density. It’s not inevitable that you will have osteoporosis,” he said.

Got milk?

The best sources of calcium and vitamin D are dairy products, Caine-Bish said. But you can take vitamin supplements, and some products, such as orange juice, crackers and cereals, are beginning to be fortified with calcium and vitamin D. Sunlight also produces vitamin D.

“It’s ideal to get your calcium from dairy products, but get it any way you can,” Caine-Bish said.

The recommended daily amount of calcium is 1,000 milligrams. That’s equal to three servings a day. Simple things, such as a cup of milk in the morning, a cup of yogurt at lunch and a cheese pizza for dinner can meet those requirements, she said.

“From what I’m seeing, students are only getting right around 600 to 800 milligrams of calcium a day,” Caine-Bish said. “It’s good they’re consuming some, but they should try to get another serving and a half.”

Fruits and vegetables are not significant sources of calcium, but they still have some, she said. Three-fourths to a cup of cooked broccoli contains 50 milligrams of calcium. Oranges and strawberries also contain minimal amounts of the mineral.

The daily recommended amount for vitamin D is 5 micrograms. D is a fat-soluble vitamin, though, so if a person consumes too much it will get stored as his or her fat.

Ready for a run?

Weight-bearing exercise is also important for a healthy bone density, Ha said. She suggests walking, running, hiking and lifting to build bone density. Leone said the muscle and exercise puts extra stress on the bones and helps them strengthen. Swimming and bicycling have no mechanical force, and therefore, do not help build bone density.

Start preparing now

Although most of the attention pertaining to bone density and osteoporosis is aimed at older women, all people should be concerned while they still have the chance to change their habits.

“It’s not very rare to have (osteoporosis), just women are more prone to it,” Ha said. “Men are not safe either if their diet is not balanced.”

Leone said, “Be vigilant. Do anything you can do to monitor (your bone density) – exercise, watch your diet, get calcium.”

Contact College and Graduate School of Education, Health and Human Services reporter Abi Luempert at [email protected].