Keeping your bones strong comes down to a handful of habits: getting enough calcium and vitamin D, doing the right kinds of exercise, eating enough protein, and avoiding a few common pitfalls that quietly drain your skeleton. The specifics matter more than most people realize, and the best time to start is earlier than you think.
Why Your Age Right Now Matters
Your bones aren’t static. They’re constantly being broken down and rebuilt, a cycle that tips in your favor when you’re young and gradually shifts the other direction as you age. During childhood and adolescence, bones grow rapidly, mostly by getting bigger rather than denser. This process builds toward what’s called peak bone mass, the maximum amount of bone you’ll ever have. Genetics, sex, and race are the biggest determinants of how much bone you ultimately build, but environmental factors like physical activity, calcium intake, and protein intake play a significant role too.
Think of peak bone mass as a savings account. The more you deposit early on, the more you can afford to lose later without running into problems. After your mid-30s, bone breakdown starts to outpace bone formation. For women, menopause accelerates this dramatically: you can lose up to 20% of your bone density within five years of menopause starting, driven by the drop in estrogen. Men lose bone too, just more gradually. Whatever your age, the goal is the same: slow the losses and protect what you have.
Calcium and Vitamin D: The Non-Negotiables
Calcium is the primary mineral your bones are made of, and vitamin D is what allows your body to absorb it from food. Without enough of either, everything else you do for your bones is less effective.
Most adults need around 1,000 mg of calcium per day, rising to 1,200 mg for women over 50 and men over 70. A cup of milk or yogurt provides roughly 300 mg, so three servings of dairy gets you close. If you don’t eat dairy, calcium-fortified plant milks, tofu made with calcium sulfate, canned sardines or salmon (with bones), and dark leafy greens like kale and bok choy are solid alternatives. Spinach contains calcium but also compounds that block its absorption, so it’s not the best source despite its reputation.
For vitamin D, the recommended daily amount is 600 IU for anyone ages 1 through 70, and 800 IU for people over 70. Infants need 400 IU. Your skin produces vitamin D from sunlight, but latitude, skin tone, sunscreen use, and time spent indoors mean many people fall short. Fatty fish, egg yolks, and fortified foods contribute some, but a supplement is often the simplest fix, especially in winter months or if you spend most of your time indoors.
Protein Matters More Than You Think
Calcium and vitamin D get all the attention, but protein is a major structural component of bone. A systematic review and meta-analysis from the National Osteoporosis Foundation found that higher protein intake had a modest protective effect on bone mineral density in the spine compared to lower intake. The effect at other skeletal sites was less clear, but importantly, the evidence showed no adverse effects from eating more protein. The old concern that high-protein diets leach calcium from bones has not held up.
You don’t need to obsess over grams. Eating protein at each meal, from sources like poultry, fish, eggs, beans, lentils, dairy, or tofu, is generally enough for most people. If you’re older and losing muscle mass, paying closer attention to protein becomes more important, since muscle and bone health are tightly linked.
The Best Exercises for Bone Strength
Not all exercise builds bone equally. Your skeleton responds to mechanical stress: when muscles pull on bones and gravity pushes down on them, bone cells get the signal to reinforce themselves. Two categories of exercise do this best.
Weight-bearing aerobic activity means any movement you do on your feet where your bones support your body weight. Walking, dancing, stair climbing, low-impact aerobics, gardening, and using an elliptical machine all count. These work directly on the bones in your legs, hips, and lower spine. Swimming and cycling, while excellent for cardiovascular health, don’t load your skeleton the same way.
Strength training uses free weights, resistance bands, or your own body weight to challenge muscles, tendons, and bones. It’s especially valuable for building the upper back muscles that support good posture, and it helps maintain bone density in areas that weight-bearing cardio doesn’t reach as well, like the spine and wrists. If you’re new to strength training, even bodyweight exercises like squats, push-ups, and rows are a meaningful starting point.
Balance and flexibility exercises won’t build bone directly, but they reduce your risk of falling, which is how most osteoporotic fractures actually happen. Tai chi, yoga, and simple single-leg standing drills are worth adding to the mix, particularly after age 50.
Habits That Quietly Weaken Bones
Some everyday habits drain calcium from your body without obvious symptoms. Eating a lot of sodium is one of the biggest culprits. There’s a direct relationship between sodium and calcium excretion: the more salt your kidneys filter out, the more calcium they pull along with it. In one controlled trial, people who cut their sodium intake from about 228 mmol per day to 68 mmol saw their daily urinary calcium loss drop from 361 mg to 271 mg. That’s a meaningful difference, roughly equivalent to a serving of dairy that your body got to keep instead of flushing away. Cutting back on processed and packaged foods, which account for most sodium in the typical diet, is the easiest way to address this.
Smoking accelerates bone loss, and heavy alcohol use (more than two drinks a day) interferes with your body’s ability to absorb calcium and disrupts the hormones involved in bone maintenance. Excessive caffeine can also slightly reduce calcium absorption, though moderate coffee intake (two to three cups a day) doesn’t appear to cause problems if your calcium intake is adequate.
Medications That Affect Your Bones
Certain prescription medications can weaken bones as a side effect, and corticosteroids (like prednisone, often prescribed for asthma, arthritis, or autoimmune conditions) are the most well-known offenders. Fracture risk increases as early as three to six months after starting these drugs. Even relatively low doses, between 2.5 mg and 7.5 mg of prednisone daily, raise the risk of spinal fractures. At 7.5 mg or more per day, the risk of vertebral fractures is five times higher than normal.
If you take corticosteroids regularly, your doctor may recommend a bone density test earlier than usual, along with extra calcium, vitamin D, or bone-protective medication. Other drugs that can affect bone include certain anti-seizure medications, some cancer treatments, and proton pump inhibitors used for acid reflux when taken long-term.
Supporting Nutrients Beyond the Basics
Vitamin K plays an underappreciated role in bone health. It activates proteins that pull calcium from your blood and deposit it into bone, directly contributing to bone quality and strength. Without enough vitamin K, those proteins stay inactive, and calcium is more likely to end up where you don’t want it (like artery walls) rather than where you do. Leafy green vegetables like kale, broccoli, and Brussels sprouts are rich in vitamin K1. Fermented foods like natto, certain cheeses, and egg yolks provide vitamin K2, which some research suggests is especially relevant for bone mineralization.
Magnesium is another mineral worth paying attention to. About 60% of the magnesium in your body is stored in bone, and it’s involved in the processes that regulate calcium balance. Nuts, seeds, whole grains, and dark leafy greens are the best dietary sources. Most people who eat a varied diet get enough, but highly processed diets tend to fall short.
How Bone Density Is Measured
A bone density test, commonly called a DEXA scan, uses low-dose X-rays to measure how much mineral is packed into a section of bone, usually at the hip and spine. The result is expressed as a T-score, which compares your bone density to that of a healthy 30-year-old of the same sex.
- T-score of -1 or higher: healthy bone density
- T-score between -1 and -2.5: osteopenia, meaning bone density is lower than normal but not yet in the osteoporosis range
- T-score of -2.5 or lower: osteoporosis
Screening is generally recommended for all women starting at age 65 and men at 70, or earlier if you have risk factors like a family history of osteoporosis, a history of fractures, long-term corticosteroid use, or early menopause. A DEXA scan is painless, takes about 10 to 15 minutes, and gives you a concrete number to track over time. If your score shows osteopenia, lifestyle changes alone can often stabilize or improve it. If it shows osteoporosis, medication combined with the same lifestyle strategies becomes the standard approach.