Calcium for Seniors: Complete Guide
Essential for bone health, but more isn't always better. Learn the right amount, timing, and important drug interactions.
Calcium and Aging Bones
After age 50, bone loss accelerates — especially in women after menopause. Calcium is the primary building block of bones, and maintaining adequate intake is crucial for preventing osteoporosis and fractures.
However, calcium supplementation has become more nuanced in recent years. We now know that more is not always better, and how you take calcium matters as much as how much you take.
Important - Calcium and Heart Health: High-dose calcium supplements (over 1,000mg/day from supplements alone) have been linked to increased cardiovascular risk in some studies. Focus on getting calcium from food first, and supplement only to fill the gap.
How Much Calcium Do You Really Need?
Daily calcium requirements:
- Adults 51-70 (men): 1,000 mg total
- Adults 51-70 (women): 1,200 mg total
- Adults 71+: 1,200 mg total
- Upper safe limit: 2,000-2,500 mg
This is TOTAL calcium from food AND supplements combined. Most Canadians get 300-700mg from food daily, so you may only need 500-700mg from supplements.
Calcium Carbonate vs Calcium Citrate
Calcium Citrate (Recommended for Seniors)
- Absorbs well with or without food
- Better choice if you take acid-reducing medications (PPIs, H2 blockers)
- Easier on the stomach, less constipation
- More expensive, larger tablets
Calcium Carbonate
- Must be taken with food for absorption
- Cheapest option, smaller tablets
- 40% calcium by weight (most concentrated)
- May cause gas, bloating, or constipation
- Less effective if you have low stomach acid
Critical Drug Interactions
Calcium interacts with many common medications. Timing is crucial:
- Thyroid medications (Synthroid) — take thyroid medication 4 hours BEFORE calcium
- Antibiotics (Cipro, tetracyclines) — take 2 hours apart
- Bisphosphonates (Fosamax, Actonel) — take bisphosphonate first thing in morning, calcium later
- Iron supplements — take at different times; calcium blocks iron absorption
- Blood pressure medications — generally okay together, but inform your pharmacist
Absorption Tips
- Split your dose — Your body can only absorb about 500mg at a time
- Take with vitamin D — Essential for calcium absorption
- Food first — Calcium from food absorbs better than supplements
- Watch the timing — Don't take calcium within 2 hours of other medications
Food Sources of Calcium
- Milk, yogurt, cheese (300mg per cup of milk)
- Fortified orange juice and plant milks
- Canned salmon/sardines with bones
- Tofu (calcium-set)
- Leafy greens (kale, bok choy — but NOT spinach)
- Fortified cereals
Frequently Asked Questions
I take a PPI for heartburn. Does that affect calcium?
Yes. Proton pump inhibitors (Omeprazole, Pantoprazole) reduce stomach acid, which is needed to absorb calcium carbonate. If you take a PPI, choose calcium citrate instead — it doesn't require stomach acid for absorption.
Can calcium supplements cause kidney stones?
The relationship is complex. Calcium from FOOD actually reduces kidney stone risk. Calcium supplements may slightly increase risk if taken in high doses without food. If you have a history of kidney stones, talk to your doctor about the right amount and timing.
Do I need calcium if I take a bone medication like Fosamax?
Yes — bisphosphonates work best when you have adequate calcium and vitamin D. However, you must separate them: take Fosamax first thing in the morning on an empty stomach, then take calcium later in the day with food.
Is coral calcium or algae calcium better?
No. These are mostly marketing. Coral calcium is just calcium carbonate from coral (and raises environmental concerns). Algae-based calcium is fine but not superior to standard calcium citrate. Don't pay premium prices for these alternatives.
Sources
- Health Canada - Dietary Reference Intakes
- National Institutes of Health - Office of Dietary Supplements
- Canadian Pharmacists Association