We work hard to keep our brains, lungs and hearts healthy, but what about the 206 structures that allow us to stand, skip and chew? It’s easy to overlook them, but bones are a crucial component of health and happiness, especially as we grow older. 

Made up mostly of collagen and calcium phosphate, bones grow denser, heavier and sturdier throughout childhood and early adulthood before reaching peak strength around age 30, according to the National Institutes of Health. But as we move into middle age, they begin to weaken and become more porous. Smoking, drinking, undereating and forgoing exercise can speed up bone loss. Eventually, osteoporosis—a serious disease that literally means “porous bones”—can result, leaving bones prone to fractures and difficult to repair. 

Currently, osteoporosis affects 10 million Americans, 8 million of whom are women, according to the National Osteoporosis Foundation. Women have a higher risk because their bones tend to be smaller and thinner than men’s, and they lose bone-protecting estrogen during menopause. Still, osteoporosis can strike anyone at any age, and it’s often difficult to detect. A fracture is often the first sign of trouble, and by that point, the disease has already advanced. 

Fortunately, you can take steps today to secure strong bones tomorrow—and we’re not just talking about guzzling milk. Here are three easy ways to keep your skeleton sturdy.

Prioritize magnesium

You’ve heard for decades that calcium is vital for building strong bones—and it is—but experts say it’s ineffective without its balancing mineral, magnesium. “Calcium makes up the greater part of bone by far, but without the proper percentage of magnesium, it becomes chalklike and brittle,” says Carolyn Dean, MD, ND, medical director of the nonprofit Nutritional Magnesium Association. “Magnesium assists calcium’s absorption and assimilation into bones. It also stimulates the hormone calcitonin, which helps to preserve bone structure and draw calcium from the blood and soft tissues back into the bones.”

According to Dean, many people actually need more magnesium than calcium, so they should take extra steps to ensure they’re getting enough. Dean touts kelp, wheat bran, wheat germ, almonds, cashews and millet as great food sources of magnesium but says it’s still tough to get enough of the mineral from food, in part because soils today are more magnesium-depleted than they once were. 

Her solution: supplements. “Most people should supplement with magnesium, since 80 percent of the population doesn’t get the recommended daily allowance, which is too low to begin with,” Dean says, adding that people under a lot of stress, women with premenstrual syndrome and athletes, who sweat out magnesium, especially need supplements. Dean likes magnesium citrate powder for its high absorbability and suggests taking 300 mg twice a day.

Get enough vitamin D

According to the National Institutes of Health (NIH), vitamin D is pivotal for bone health because it promotes calcium absorption in the intestines, which in turn enables proper bone growth and remodeling. Therefore, when vitamin D is lacking, the body doesn’t process and reserve enough calcium to keep bones strong. 

The body doesn’t manufacture vitamin D on its own, so it must be obtained from diet and the sun. But because few foods naturally contain vitamin D, and heightened skin cancer concerns cause many people to shun the sun, millions of Americans are now vitamin D–deficient—especially during the winter months when sunlight’s already sparse. 

To ensure sturdy bones, NIH suggests eating vitamin D-rich salmon, tuna and other oily fish and vitamin D-fortified foods such as low-fat dairy, soymilk and yogurt, and taking a daily vitamin D supplement. The Foundation for Osteoporosis Research and Education recommends 1,000 to 2,000 IU per day. Although this dosage exceeds the Institute of Medicine’s recently updated dietary reference intake of 600 IU, experts agree that this higher range is safe and more effective. 

Do weight-bearing exercise

Daily exercise offers your bones a two-pronged perk. First, it builds bone mass, and second, it helps maintain muscle strength, coordination and balance, which in turn prevents falls and other bone-breaking accidents. 

Michele Olson, PhD, professor of exercise science at Auburn University at Montgomery, says weight-bearing workouts that force legs and arms to work against gravity to bear body weight are best for strengthening bones. These include jogging, stair climbing, dancing, racquetball and walking—but not cycling or swimming, which are great aerobic workouts but don’t require bones and muscles to uphold your body.

“The greater the impact, the more the bones adapt upward and become denser—and the older we get, the more we need this,” she says. “Do weight-bearing, bone-loading exercise for at least 30 minutes most days of the week. You can build up to 45 or 60 minutes, but be careful not to overexert or overpound your body.”

Olson also suggests mixing up modalities. For instance, spice up your evening hiking routine with a twice-a-week step class. “The impact going on and off the step is good for the spine and hips,” Olson says. Or, if you walk on a treadmill, she recommends raising the ramp to a 7 percent grade every five minutes, hoofing it “uphill” for three minutes, lowering it back down and repeating throughout the 30-minute exercise.