Preventing Steroid-Induced Osteoporosis: Calcium, Vitamin D, and Bisphosphonates

Why Steroids Put Your Bones at Risk

If you’re taking steroids-whether for asthma, rheumatoid arthritis, lupus, or another chronic condition-you’re not just managing inflammation. You’re also quietly weakening your bones. Glucocorticoid-induced osteoporosis (GIOP) is the most common type of secondary osteoporosis, affecting 30% to 50% of people on long-term steroid therapy. And it doesn’t wait years to strike. Bone loss can start within 3 to 6 months of starting even low doses-like 2.5 mg of prednisone daily.

Unlike regular osteoporosis, which happens slowly as we age, GIOP attacks bone in two ways at once. First, it shuts down the cells that build bone (osteoblasts), cutting new bone formation by up to 70%. Second, it wakes up the cells that break bone down (osteoclasts), speeding up bone loss by 30%. This double hit is why fractures happen so fast. About 12% of people taking 7.5 mg or more of prednisone daily will have a spinal fracture within the first year.

The Foundation: Calcium and Vitamin D

Before you even think about pills that stop bone loss, you need the basics: calcium and vitamin D. These aren’t optional add-ons. They’re the floor your treatment stands on. The American College of Rheumatology (ACR) says every adult starting long-term steroids should get 1,000 to 1,200 mg of calcium daily and 600 to 800 IU of vitamin D. If your vitamin D level is below 30 ng/mL (which is common), bump it up to 800-1,000 IU daily.

Calcium isn’t just about dairy. If you can’t get enough from food-yogurt, cheese, leafy greens, fortified orange juice-take a supplement. Split your dose: 500 mg at a time, because your body can’t absorb more than that at once. Vitamin D is trickier. Sunlight helps, but most people don’t get enough, especially if they’re indoors a lot or live far from the equator. A simple blood test can tell you if you’re deficient. Don’t guess. Test it.

Without these two, even the strongest bone drugs won’t work well. Think of calcium and vitamin D as the bricks and mortar. Without them, your bones are just dust.

Bisphosphonates: The First-Line Shield

If you’re on steroids for more than 3 months and you’re 40 or older-or you’ve had a fracture before-bisphosphonates are your go-to treatment. These drugs slow down bone breakdown. They don’t rebuild bone, but they stop it from disappearing too fast.

The most common ones are alendronate (Fosamax) and risedronate (Actonel), taken once a week. Studies show they increase bone density in the spine by 3-4% in the first year, while untreated patients lose bone. They cut the risk of spinal fractures by nearly half. For someone on high-dose steroids, that’s life-changing.

But there’s a catch. These pills are picky. You have to take them on an empty stomach with a full glass of water. Then stay upright for at least 30 minutes. No lying down. No eating. No other meds. Skip these steps, and you risk serious heartburn or even esophageal damage. About 1 in 5 people can’t tolerate them because of this.

If you can’t take oral bisphosphonates, there’s an alternative: zoledronic acid. It’s given as a one-time IV infusion once a year. No daily pills. No waiting around after taking it. And it works better than oral versions at protecting the hip-something oral bisphosphonates don’t do as well.

When Bisphosphonates Aren’t Enough

Not everyone responds the same. If you’re under 40, have a T-score below -2.5, or already had a fracture, bisphosphonates might not be enough. That’s where teriparatide (Forteo) comes in. This isn’t a bone-preserving drug. It’s a bone-building one. It’s a synthetic version of parathyroid hormone, injected daily under the skin.

Studies show it’s dramatically better than bisphosphonates for high-risk patients. In one trial, only 0.6% of people on teriparatide had a new spinal fracture over 18 months. In the bisphosphonate group? 6.1%. That’s a tenfold difference. It’s also the only drug proven to rebuild bone density faster-up to 16% in the spine over 18 months.

But it’s expensive. A month’s supply costs around $2,500 in the U.S., compared to $250 for generic alendronate. And it’s only approved for two years. After that, you switch to a bisphosphonate to hold the gains. It’s also not for everyone. If you’ve had bone cancer, radiation to the skeleton, or Paget’s disease, you can’t use it.

Other Options: Denosumab and Newer Drugs

Denosumab (Prolia) is another choice. It’s a shot every six months that blocks bone breakdown. It cuts spinal fracture risk by 79%-better than bisphosphonates. It’s easier than daily pills and works even if your kidneys are weak. But it’s not perfect. If you stop it, you can lose bone fast. That means you need to switch to another drug right away.

Newer drugs like abaloparatide (Tymlos) are showing even better results than teriparatide in early trials. It’s not yet widely used for steroid-induced osteoporosis, but it’s coming. And research is now looking at combining drugs-starting with teriparatide to rebuild, then switching to zoledronic acid to protect. Early results suggest this could give you the best of both worlds.

Monitoring and Long-Term Thinking

You can’t just start treatment and forget it. You need to track your bone density. A DXA scan (a special type of X-ray) should be done when you start steroids, then again at 12 months. If your bone density drops more than 5% in a year, your treatment needs to change.

Also, pay attention to how you’re taking your meds. Half of people stop their oral bisphosphonates within a year because of side effects or just forgetting. That’s why IV options like zoledronic acid are so valuable. They cut adherence problems by nearly 40%.

Long-term use of bisphosphonates (over 5 years) can bring rare risks: atypical thigh fractures and jaw bone death. These are extremely rare-about 1 in 10,000 to 1 in 100,000 people. But your doctor should review your treatment every 3-5 years to see if you still need it.

What Most Doctors Miss

Here’s the ugly truth: only about 1 in 5 people on long-term steroids get their bones checked. Only 19% get the right treatment within 3 months of starting steroids. Even though guidelines have been clear since 2001, most patients are left unprotected.

Why? Doctors are busy. Patients don’t know the risk. And many think, “I’m young, I feel fine, why worry?” But bone loss doesn’t hurt until it breaks. And once a spine fractures, it changes your life-height loss, chronic pain, loss of independence.

If you’re on steroids, don’t wait for a fracture to happen. Ask your doctor for a bone density test. Ask if you need calcium and vitamin D. Ask if you should be on a bisphosphonate. Don’t assume they’ll bring it up. They might not.

Bottom Line: Your Action Plan

Here’s what you need to do right now:

1. Get your vitamin D level tested. If it’s below 30 ng/mL, start 800-1,000 IU daily.
2. Take 1,000-1,200 mg of calcium daily-split into two doses.
3. If you’re 40+ and taking ≥2.5 mg prednisone daily for 3+ months, ask about bisphosphonates.
4. If you’re under 40 but have a prior fracture or very low bone density, ask about teriparatide.
5. Get a DXA scan within 6 months of starting steroids, then yearly.
6. If you’re on oral bisphosphonates, follow the dosing rules exactly-upright, empty stomach, no food for 30 minutes.

Steroids save lives. But they don’t have to steal your mobility. With the right steps, you can protect your bones and keep living strong.