Calcium & vitamin D

supportive bone health · say “KAL-see-um and vitamin D”

Supportive

The foundation for your bones.

Calcium and vitamin D are the base layer of bone protection on steroids. Food comes first, with supplements to fill the gap to your target.

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What it is

The base layer of bone protection.

Calcium and vitamin D are not treatments for myositis itself, but they are the foundation of protecting your bones while you take steroids, and the bone medications above work best on top of them. Vitamin D also matters for muscle, and low levels have been linked to more active disease.

How to take it

Aim for about 1000 to 1200 mg of calcium a day in total, counting food first and topping up with a supplement only to reach the target.
Vitamin D is often taken at 1000 to 2000 IU a day, or as your doctor directs based on your blood level.
Split calcium supplements into smaller amounts with meals for better absorption.
You do not need to over-supplement; more is not better, and your target is individual.

What to expect

These support bone health quietly in the background; you will not feel a change.
Your vitamin D level may be checked and the dose adjusted.
They are usually continued for as long as you are on steroids or a bone medication.

Benefits

How it helps you.

Supports bone density

The base layer that steroid-related bone protection is built on.

Makes bone medicines work

Bisphosphonates and denosumab work best with adequate calcium and vitamin D.

Vitamin D and muscle

Correcting low vitamin D supports muscle and general health.

Simple and low-cost

Available over the counter, guided by your target.

Risks & side effects

What you should know.

Your doctor prescribed this because the expected benefits outweigh the risks for your situation. Here is the honest, full picture.

Common side effects

Constipation or bloating

Calcium supplements can cause this. Splitting doses and taking with food helps.

Mild stomach upset

Occasionally, usually mild.

Serious but uncommon

Kidney stones

Very high calcium intake can raise the risk. Stay within your target rather than over-supplementing.

High blood calcium

Rare with sensible doses; more likely if very high doses are combined with high vitamin D.

Staying safe

Monitoring and precautions.

Regular monitoring

Vitamin D level may be checked and the dose adjusted.
Blood calcium may be checked if you are also on a bone medication.
Your total calcium target counts food plus supplements, not supplements alone.

Daily precautions

Count food first. Dairy, fortified plant milks, tinned fish with bones, and leafy greens all contribute.
Do not over-supplement. Aim for your target rather than the highest dose.
Take calcium with meals, split through the day.
If you take a bisphosphonate tablet, do not take calcium at the same time; separate them.

When to call your doctor

Contact the clinic if you notice:

Kidney stone symptoms

Severe flank pain or blood in the urine. Seek care.

Persistent constipation

That does not settle with diet changes; your dose can be adjusted.

Numbness or cramps

May signal calcium is too low; report it, especially if you are on denosumab.

Pregnancy & breastfeeding

Calcium and vitamin D are safe and often recommended in pregnancy and breastfeeding at usual doses. Confirm the right amounts with your doctor.

This guide is for education, not medical advice. Myositis treatment is individual, and many of these medications are used based on specialist experience and evidence rather than a formal Canadian myositis indication. Never start, stop, or change a medication without your own doctor. Your doses and choices are decided with your care team at the Centre.

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