Why Long-Term Steroids Can Break Your Bones

You’re on prednisone or another corticosteroid because you need it - maybe for asthma, rheumatoid arthritis, or an autoimmune condition. But if you’ve been taking it for more than three months, your bones are quietly weakening. This isn’t a myth. It’s called glucocorticoid-induced osteoporosis (GIOP), and it’s the most common type of secondary osteoporosis. Within just three to six months of starting daily steroids, your fracture risk jumps by 70 to 100%. That’s faster than most people realize. By the end of the first year, you could lose 5 to 15% of your bone density, especially in your spine. And unlike regular osteoporosis, this one hits hard and fast.

How Steroids Attack Your Bones

Steroids don’t just reduce inflammation - they mess with your body’s bone-building system. They shut down osteoblasts, the cells that make new bone, and make them die off faster. At the same time, they keep osteoclasts - the cells that break down bone - alive longer. It’s like turning off the construction crew while hiring more demolition workers. Your body also absorbs less calcium from food, leaks more through your kidneys, and stops responding properly to physical activity. Even walking or light lifting becomes less effective at strengthening bones. Studies show weight-bearing exercise loses about 25% of its bone-protecting power when you’re on long-term steroids.

Who’s at Risk - And When It Starts

If you’re taking 2.5 mg or more of prednisone (or its equivalent) every day for three months or longer, you’re in the high-risk group. That’s not a high dose - it’s a common starting dose for many conditions. But if you’re on 7.5 mg or more daily, your fracture risk doubles. And here’s the scary part: every extra 1 mg of daily prednisone cuts your spine bone density by 1.4% each year. That’s not slow aging - that’s accelerated bone decay. Men are especially at risk because they’re less likely to get screened or treated. Only 44% of men on long-term steroids get any prevention advice, compared to 76% of women. And yet, men often have worse outcomes.

The Non-Negotiables: Diet, Movement, and Lifestyle

Before you even think about pills, fix the basics. You need at least 1,000 to 1,200 mg of calcium daily. That’s about three servings of dairy, or fortified plant milk, leafy greens, or almonds. If you can’t get it from food, take a supplement. Vitamin D is just as critical. Most people need 800 to 1,000 IU daily to keep blood levels above 20 ng/mL. Without enough vitamin D, your body can’t absorb calcium - no matter how much you take. Don’t rely on sunlight alone. Even in Bristol, winter sun won’t cut it.

Exercise isn’t optional. You need weight-bearing activity at least five days a week - walking, stair climbing, dancing, or resistance training with bands or light weights. Thirty minutes a day. It’s not about lifting heavy; it’s about keeping your bones under stress. And if you smoke? Quit. Smoking alone increases fracture risk by 25 to 30%. Cut alcohol to under three units a day. More than that? It directly harms bone cells.

Medications That Actually Protect Your Bones

Calcium and vitamin D are the foundation, but they’re not enough alone if you’re on long-term steroids. The first-line drug is a bisphosphonate - risedronate or alendronate. Risedronate, taken daily or weekly, cuts spine fractures by 70% and other fractures by 41%. Zoledronic acid, given as a yearly IV drip, boosts spine bone density by 4.5% in a year. Denosumab, injected every six months, adds 7% to spine density. And for those with severe bone loss or prior fractures, teriparatide - a daily injection - is the strongest option. It increases spine density by 9.1% in a year, nearly double what bisphosphonates do. The Royal Osteoporosis Society says teriparatide works 2.3 times better than alendronate in high-risk steroid users.

Why So Many People Are Still Getting Fractures

Here’s the broken part: even though guidelines have existed for over 20 years, only about 15% of people on long-term steroids get care that matches what doctors know works. Why? Many don’t know they’re at risk. One study found 45% of patients think bone loss from steroids is unavoidable. Others don’t get tested. Only 31% have a bone density scan. Doctors don’t always talk about it. In the UK, only 22% of GPs feel properly informed when a rheumatologist prescribes steroids. And even when prescriptions are given, adherence drops fast. Only 40% of people keep taking calcium and vitamin D after a year. Bisphosphonate use falls to 45% by year one, mostly because of stomach upset. But here’s the good news: when systems change, outcomes improve. At one VA hospital, adding automatic EHR alerts and mandatory prevention order sets boosted guideline-concordant care from 40% to 92%.

What You Should Do Right Now

If you’re on steroids for three months or more, ask for these three things:

1. A bone density scan (DXA) - now, not later.
2. A prescription for calcium (1,000-1,200 mg) and vitamin D (800-1,000 IU) if you’re not already taking them.
3. A discussion about bisphosphonates or another bone drug - especially if your dose is above 7.5 mg daily, or if you’ve had a fracture.

Don’t wait for symptoms. Osteoporosis doesn’t hurt until you break a bone. And once you do, recovery is harder, especially if you’re still on steroids. The best time to act is within the first three to six months of starting treatment. That’s when bone loss is fastest - and most preventable.

Real Talk: What Works in Real Life

One patient I know, a 58-year-old man from Bristol on 10 mg prednisone for lupus, skipped the bone scan because he felt fine. A year later, he fractured his spine lifting a suitcase. He didn’t realize his posture had changed - he’d lost nearly an inch in height. After starting risedronate, calcium, vitamin D, and daily walks, his spine density improved by 5% in 18 months. He still takes steroids, but now he has a plan. That’s the difference. You can’t always stop the steroids. But you can stop the bone loss.

Final Thought: It’s Not About Avoiding Steroids - It’s About Managing the Risk

Steroids save lives. The goal isn’t to quit them unless your doctor says so. The goal is to protect your bones while you’re on them. That means knowing your dose, getting tested, taking your supplements, moving your body, and asking for the right drugs. If your doctor doesn’t bring it up, bring it up yourself. Your bones can’t speak for themselves - but you can.