Pound for pound, bone is stronger than concrete. But that amazing strength starts to diminish as we age. If you're a woman over 50, you're more likely to go to the hospital for a fracture caused by a disease that causes brittle bones than you are for breast cancer, stroke or a heart attack, according to a new study from Georgetown University.

Even being young doesn't necessarily protect us. Bone begins to weaken in our 30s, and the odds are tilted against women. After age 50, your odds for a fracture from brittle bone disease — also known as osteoporosis — are 25 percent for men and a whopping 50 percent for women.

Related: Signs That Your "Sprain" Might Be Something More Serious

What works for shoring up bones? Exercise that puts “good stress” on your bones — especially ones like jumping — can go a long way. So can changing your diet. Here’s a nutrition strategy that works, according to experts.

Don't skimp on calcium, but get it from food

Aim for 1,000 milligrams (mg) of calcium a day if you’re a woman age 50 or younger or a man younger than 70, according to the Institute of Medicine. If you're a woman over 50 or a man over 70, make that 1,200 mg a day. The National Osteoporosis Foundation (NOF) and prominent bone-health experts endorse those calcium levels. What’s new: These groups now say it’s smart to get most, and preferably all, of your calcium from food.

Recent studies suggest getting most calcium from supplements could increase the risk for heart disease in men. Other research has found that supplements alone may not strengthen bones, and that getting extra calcium from pills won’t make bones any stronger.

Your plan: Figure out how much calcium you’re already getting from food, then add more good sources. Most of us get 250 mg a day from foods like broccoli, kale, nuts and bread. You’ll get about 300 mg in eight ounces of milk, six ounces of yogurt or an ounce of cheese.

But what if you're vegetarian? According to the Vegetarian Resource Group, great nondairy sources include blackstrap molasses (400 mg in 2 tablespoons), turnip greens or collards (250 to 350 mg in one cooked cup), calcium-fortified alternative milks and yogurts and tofu processed with calcium (200 to 420 mg in two ounces).

If you’re still falling short, a calcium supplement that gets you to your goal is OK, experts say. For best absorption, take up to 500 to 600 mg with a meal.

Add plenty of vitamin D

Vitamin D helps your body incorporate calcium into the honeycomb-like structures within bone that keep your skeleton strong. That’s why plenty of calcium supplements also contain D.

Now, the NOF and Harvard bone experts say you may need more vitamin D than you think. The osteoporosis foundation suggests aiming for 400 to 800 IU before age 50, and 800 to 1,000 IUs per day after that.

Your plan: It's virtually impossible to get the vitamin D you need every day from food. And while your skin does produce D when exposed to sunlight, most of us don’t get enough bright sun exposure to make enough (we either spend too much time indoors, live too far north or block the rays with sunscreen). A daily vitamin D supplement is probably your best bet, the NOF advises.

Related: Are Your Vitamin D Levels Too Low?

Don't forget potassium and vitamin K

A recent Swedish study found that getting enough potassium helps keep bones strong. The mineral may help by reducing acid levels that promote bone loss. Meanwhile, low levels of vitamin K have been linked with a higher risk for bone fractures.

Your plan: Aim for4,700 mg of potassium and 90 micrograms of vitamin K per day. Most of us don’t get enough of either nutrient. Foods that deliver potassium include bananas, potatoes (with the skin), prunes, orange juice, tomato juice, raisins, acorn squash, lima beans and spinach. Lettuce and other leafy greens are top sources of K. 

Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.