You can eat the same amount of calcium you always have and still absorb less of it as you get older.
It is one of the less obvious changes that comes with ageing. Calcium absorption becomes less efficient over time, and for women there can be an additional change around menopause.
That matters because calcium is not simply something you eat. It has to make its way from your food, through the intestine and into the bloodstream before your body can use it.
So what changes? There is no single switch that suddenly flips at 50. Instead, several biological factors can affect how effectively calcium is absorbed and used.
Three reasons calcium can become harder to absorb
The calcium absorption system becomes less efficient
Your intestine absorbs calcium in two main ways: active transport through intestinal cells and passive movement between them.
Vitamin D plays an important role in the active pathway. Its active form, calcitriol, helps regulate the proteins responsible for transporting calcium from the intestine into the body.
Research shows that calcium absorption efficiency tends to decline with age. In one study of healthy postmenopausal women aged 40 to 87, calcium absorption was significantly lower with increasing age and was 28% lower in women over 75 than in the younger women studied.
Low stomach acid becomes more common
It is often said that everyone naturally produces less stomach acid simply because they get older. The science is more nuanced than that.
Healthy ageing alone does not necessarily cause a major reduction in stomach acid. However, low stomach acid becomes more common in older adults because conditions such as atrophic gastritis and H. pylori infection become more prevalent, and acid-suppressing medications are also widely used.
Why can that matter for calcium? Some forms depend more heavily on stomach acid to dissolve. Calcium carbonate, for example, is less soluble when stomach acid is low. Calcium citrate is less dependent on stomach acid and can therefore be easier to absorb for people with low acid levels.
Menopause changes both calcium absorption and bone turnover
For women, menopause introduces another important change.
Research has shown a decline in intestinal calcium absorption around the menopausal transition. Oestrogen loss also has direct effects on bone itself, increasing bone resorption so that bone can be broken down faster than it is rebuilt.
These are related but separate effects. Reduced calcium absorption is one part of the picture; the direct effect of declining oestrogen on bone remodelling is another.
So how much calcium do you actually need?
Australian recommendations differ according to age and sex.
| Age | Recommended calcium intake |
|---|---|
| Women 51–70 | 1,300 mg/day |
| Women 70+ | 1,300 mg/day |
| Men 51–70 | 1,000 mg/day |
| Men 70+ | 1,300 mg/day |
The key point isn't that everyone over 50 suddenly stops absorbing calcium properly. It's that the margin for error becomes smaller.
If absorption becomes less efficient while calcium intake also falls, it becomes harder to consistently provide the body with what it needs.
Getting more from the calcium you eat
There is no single trick that fixes calcium absorption. A better approach is to make sure the pieces that support normal calcium and bone metabolism are in place.
Include calcium-rich foods regularly across the day, such as dairy foods, calcium-fortified alternatives, calcium-set tofu, sardines and other suitable sources.
Vitamin D plays an important role in active intestinal calcium absorption as well as normal bone mineralisation.
Calcium absorption varies between foods. Compounds such as oxalates and phytates can reduce the amount absorbed from some plant foods.
People with low stomach acid may absorb calcium citrate more easily than calcium carbonate. Speak with your GP, pharmacist or dietitian if you're unsure what is appropriate for you.
Calcium is only one part of the bone-health picture
Strong bones aren't built from calcium alone.
Vitamin D is needed for normal calcium absorption and bone mineralisation. Magnesium also plays a role in normal bone structure and mineral metabolism. And protein is important for maintaining the muscle and physical function that help keep us active as we age.
That is why looking at nutrition as a system makes more sense than focusing on a single nutrient in isolation.
More than protein
Protein Boost isn't designed to replace a calcium-rich diet. It's designed to make useful nutrients easier to include as part of one.
The takeaway? After 50, calcium isn't only about how much you eat. Age, menopause, Vitamin D status, digestive health, medications and the source of calcium can all influence how much ultimately becomes available to your body.
Getting the basics right becomes more important, not less.
Smarter nutrition for healthy ageing
21 g protein plus calcium, Vitamin D, magnesium, prebiotic fibre and digestive enzymes.
Shop Health Protein Boost →This article is for general health education and does not constitute medical advice. Individual calcium requirements and absorption can vary according to diet, Vitamin D status, age, menopause, digestive conditions and medication use. If you are concerned about bone health, calcium intake, Vitamin D status or osteoporosis risk, speak with your GP, pharmacist or accredited practising dietitian.
References
- Australian Government, National Health and Medical Research Council and New Zealand Ministry of Health. Nutrient Reference Values for Australia and New Zealand — Calcium. eatforhealth.gov.au
- National Institutes of Health, Office of Dietary Supplements. Calcium — Fact Sheet for Health Professionals. ods.od.nih.gov
- National Institutes of Health, Office of Dietary Supplements. Vitamin D — Fact Sheet for Health Professionals. ods.od.nih.gov
- Nordin BEC, Need AG, Morris HA, O'Loughlin PD, Horowitz M. Effect of age on calcium absorption in postmenopausal women. American Journal of Clinical Nutrition. 2004;80(4):998–1002. pubmed.ncbi.nlm.nih.gov/15447911
- Heaney RP, Recker RR, Stegman MR, Moy AJ. Calcium absorption in women: relationships to calcium intake, estrogen status, and age. Journal of Bone and Mineral Research. 1989;4(4):469–475. pubmed.ncbi.nlm.nih.gov/2816496
- Need AG, Morris HA, Horowitz M, Nordin BEC. Effect of perimenopause on calcium absorption: a longitudinal study. Climacteric. 2002. pubmed.ncbi.nlm.nih.gov/11910650
- Kositanurit W, et al. Age-related decline of gastric secretion: facts and controversies. 2025 review. pmc.ncbi.nlm.nih.gov/articles/PMC12292447
References are provided for informational transparency. This article is intended for general health education and does not constitute medical advice.
