Key Takeaways
  • Calcium requirements vary significantly by age and life stage — from 500mg in young children to 1,300mg in teenagers and older adults
  • 40% of peak bone mass is acquired during puberty — adequate calcium intake during adolescence is critical
  • Older adults need more calcium because absorption from the intestine declines with age
  • Food sources are preferred over supplements; supplements should only make up part of daily requirements
  • After bariatric surgery, calcium absorption is often reduced — supplementation is typically essential

Why Calcium Matters Across Every Life Stage

Calcium is the most abundant mineral in the human body. It is essential not just for strong bones and teeth, but also for muscle function, nerve transmission, and cardiovascular health. The amount you need changes significantly across your lifetime — and failing to meet your requirements at key stages can have long-term consequences for bone health.

Healthy Bones Australia provides recommended daily calcium intake guidelines for Australians. These are reproduced below as a practical reference:

Life Stage Age Group Daily Calcium (mg)
Children 1–3 years 500 mg
Children 4–8 years 700 mg
Adolescents 9–18 years 1,300 mg
Adults 19–50 years (women) / 19–70 years (men) 1,000 mg
Pregnant / Breastfeeding 14–18 years 1,300 mg
Pregnant / Breastfeeding 19–50 years 1,000 mg
Older Adults 51+ years (women) / 71+ years (men) 1,300 mg

Source: Healthy Bones Australia — recommended daily calcium intakes for the Australian population.

Calcium Across the Life Stages

Children
Building the foundation

Growing bones require consistent daily calcium from an early age. Requirements increase as children grow, supporting skeletal development and density.

Teens
The most critical window — 1,300mg daily

40% of peak bone mass is acquired during puberty. The teenage growth spurt creates the highest calcium demands of any life stage. Falling short during these years can permanently reduce peak bone density.

Adults
Maintaining what you've built

Peak bone mass is achieved by the early twenties. Adequate calcium intake in adulthood maintains bone strength and reduces the rate of bone loss over time.

Older adults
Requirements increase again — 1,300mg daily

As we age, the intestine absorbs calcium less efficiently, and more calcium can be lost through the kidneys. This is why the daily recommendation rises again after 51 (women) and 71 (men).

Best Food Sources of Calcium

Where possible, calcium should come from food sources rather than supplements. Here are some of the best dietary sources:

🥛
Milk (250ml)
~300 mg
🧀
Hard cheese (40g)
~300 mg
🥣
Yoghurt (200g)
~250–350 mg
🐟
Tinned salmon with bones
~220 mg
🥦
Broccoli (1 cup, cooked)
~60 mg
🥜
Almonds (30g)
~75 mg
🫘
Tofu (firm, 100g)
~200–400 mg
🥤
Fortified plant milk (250ml)
~300 mg

Should You Take a Supplement?

Excessive calcium intake from supplements is not recommended — very high doses can increase the risk of kidney stones and may have cardiovascular implications. Supplements should only make up part of daily requirements, and food sources should always be prioritised where possible.

Important: Do not take calcium supplements without first checking with your doctor or dietitian. Your individual needs depend on your age, health history, diet, and any medications you may be taking.

Calcium After Bariatric Surgery

For patients who have undergone bariatric surgery, calcium absorption is often significantly reduced because the gastrointestinal tract has been altered. This means that even a good dietary intake of calcium may not be sufficient — and supplementation is typically an essential part of long-term post-surgical care.

Post-bariatric calcium requirements are higher than for the general population and require careful monitoring through regular blood tests. Your MedSurg doctor and dietitian will guide you on the correct type (calcium citrate is generally better absorbed post-surgery than calcium carbonate) and dose for your needs.

Medical disclaimer: This article is for general informational purposes only and does not constitute medical or nutritional advice. Calcium requirements vary between individuals. Please consult your doctor or a qualified dietitian before starting or adjusting calcium supplementation.

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