Prednisone is a powerful corticosteroid medication prescribed for a wide range of conditions, including autoimmune disorders, severe allergies, and inflammatory diseases. While highly effective at reducing inflammation, its use, especially long-term, carries a significant risk of side effects, one of the most serious being accelerated bone loss. This bone loss can lead to glucocorticoid-induced osteoporosis (GIO) and increase the risk of fractures. Understanding how much calcium should I take while on prednisone is a critical part of a proactive strategy to safeguard your bone density.
Why Prednisone Affects Your Calcium Levels and Bone Health
Prednisone affects bone health through several complex mechanisms:
- Decreased Calcium Absorption: It reduces the body's ability to absorb calcium from the intestines. This means that even if you consume adequate dietary calcium, less of it is available for your body to use.
- Increased Calcium Excretion: The medication also increases the amount of calcium that is excreted by the kidneys through urine.
- Disrupted Bone Remodeling: Prednisone disrupts the natural balance of bone remodeling, the continuous process of old bone tissue being removed (resorption) and new bone tissue being formed (formation). It stimulates the cells that break down bone (osteoclasts) and suppresses the cells that build new bone (osteoblasts), leading to a net loss of bone mass.
This rapid bone loss is most pronounced in the first few months of starting oral prednisone but continues for as long as the medication is used, even at low doses (as little as 2.5 mg per day).
Recommended Calcium and Vitamin D Intake While on Prednisone
Given the impact of prednisone on bone health, supplementation is a standard part of therapy for most patients on long-term or high-dose courses. Medical guidelines from organizations like the American College of Rheumatology (ACR) recommend specific intake targets for patients on corticosteroids:
- Total Calcium: An increased daily intake of elemental calcium from a combination of diet and supplements is generally recommended. It's important to remember this is a total daily intake, and a healthcare provider can help you determine the appropriate amount after assessing your dietary intake.
- Vitamin D: Alongside calcium, vitamin D is essential for proper calcium absorption and is also affected by prednisone. The ACR recommends adequate daily intake of vitamin D. A blood test can help determine if you have a deficiency that requires additional supplementation.
Choosing the Right Calcium Supplement
If dietary intake isn't enough, supplements are necessary. The two most common forms are calcium carbonate and calcium citrate, which have different characteristics.
| Feature | Calcium Carbonate | Calcium Citrate |
|---|---|---|
| Elemental Calcium | High (40%) | Lower (21%) |
| Absorption | Requires stomach acid; best taken with food. | Can be taken with or without food. |
| Cost | Generally less expensive. | Typically more expensive. |
| Side Effects | More likely to cause gas, bloating, or constipation in some individuals. | Better tolerated by people who experience digestive side effects from carbonate. |
| Considerations | May not be ideal for those on acid-reducing medications. | Preferred for individuals with achlorhydria (low stomach acid) or those on proton pump inhibitors. |
Regardless of the type, your body can absorb a limited amount of calcium at one time. If your daily supplement dose is high, it may need to be split into two or more smaller doses throughout the day to maximize absorption.
Optimizing Calcium with Diet and Lifestyle
Supplements are often necessary, but a diet rich in calcium-containing foods should be the foundation of your intake. Here are some excellent dietary sources:
- Dairy Products: Milk, yogurt, and cheese are classic and reliable sources of calcium.
- Fortified Foods: Many juices, cereals, and plant-based milks (like soy and almond) are fortified with calcium.
- Leafy Greens: Kale, broccoli, and bok choy contain significant amounts of calcium.
- Canned Fish: Salmon and sardines with bones are excellent sources.
In addition to dietary measures and supplementation, lifestyle changes can further support bone health while on prednisone:
- Weight-Bearing Exercise: Activities like walking, jogging, and strength training help build and maintain bone density.
- Avoid Smoking: Smoking is a major risk factor for osteoporosis and should be avoided.
- Limit Alcohol: Excessive alcohol consumption can interfere with calcium absorption and bone formation.
- Fall Prevention: Taking steps to prevent falls is especially important for those at higher risk of fracture.
The Role of Prescription Medications for Severe Bone Loss
For some patients, particularly those at high fracture risk due to age, pre-existing osteoporosis, or long-term/high-dose prednisone use, calcium and vitamin D alone may not be sufficient. In these cases, a doctor may prescribe additional medications to prevent or treat GIO. These can include:
- Bisphosphonates: Such as alendronate or risedronate, which slow down bone resorption.
- Other options: Teriparatide or denosumab may be used for patients at very high risk.
Your healthcare provider will perform a bone density test (DXA scan) to assess your risk and determine if these additional measures are necessary. The American College of Rheumatology provides comprehensive guidelines for assessing and managing glucocorticoid-induced osteoporosis based on individual risk factors.
Conclusion
Taking prednisone, especially over an extended period, significantly impacts bone health by reducing calcium absorption and accelerating bone loss. Therefore, it is crucial to address your calcium and vitamin D intake proactively. Most guidelines recommend an increased daily intake of calcium and adequate vitamin D, sourced from a combination of diet and supplements. By working closely with your healthcare provider to implement a comprehensive bone health plan, including proper nutrition, supplementation, and appropriate exercise, you can effectively minimize the risk of glucocorticoid-induced osteoporosis and safeguard your skeletal health for the long term.
