Calcium and bone: the milk question

This is the example the whole page was built around. Milk is a good source of calcium — that is not in dispute, and it is the reason the advice exists. The question is what happens to bones and to people when they drink more of it, and that question has been asked in a way that can be answered.

A systematic review of cohort studies found most reported no association between dietary calcium and fracture: 14 of 22 studies for total fracture, 17 of 21 for hip fracture, 7 of 8 for vertebral fracture and 5 of 7 for forearm fracture. [1]

In the same review, most cohort studies also found no association between fracture and milk intake (25 of 28) or dairy intake (11 of 13). [1]

The review concludes that dietary calcium intake is not associated with fracture risk, that there is no clinical trial evidence that increasing calcium from dietary sources prevents fractures, and that the evidence for calcium supplements is weak and inconsistent. [1]

A companion review looked at the marker instead of the outcome. Bone mineral density is what the calcium advice is aimed at, and it does move.

A companion meta-analysis of 59 randomised trials in people over 50 found that increasing calcium from food raised bone mineral density by 0.6% to 1.0% at the total hip and total body after one year, and that the increases were unlikely to lead to a clinically significant reduction in fracture risk. [2] [2]

That is the mechanism doing exactly what it promised, at a size that does not reach the thing a person cares about. The gap between the two is the whole point of this section.

Meanwhile the cohort that gives plant-based diets their best heart-disease result gives them their worst bone result, in the same people, in the same follow-up.

In the ProspecTive EPIC-Oxford cohort, followed for an average of 17.6 years, vegans had a higher risk of hip fracture than meat eaters (hazard ratio 2.31, 95% confidence interval 1.66 to 3.22), equivalent to 14.9 more cases per 1000 people over 10 years. [3]

The same cohort study reports that the associations were stronger without adjustment for body mass index and were slightly attenuated but remained significant after additional adjustment for dietary calcium or total protein. [3]

Milk itself has been followed against both outcomes at once, in Sweden, in two large cohorts with long follow-up.

In a Swedish cohort of 61,433 women followed for a mean of 20.1 years, every daily glass of milk was associated with an adjusted hazard ratio for all-cause mortality of 1.15 (95% confidence interval 1.13 to 1.17), and higher milk consumption was associated with no reduction in any fracture (1.02, 1.00 to 1.04) or hip fracture (1.09, 1.05 to 1.13). [4] [4]

That result is one cohort of one population, and it should be read as one result rather than as a verdict. When the prospective studies were pooled, the pooling turned out not to be legitimate.

A meta-analysis of 12 prospective studies of non-fermented milk found such substantial heterogeneity for all-cause mortality (I² = 94%) that estimating a pooled hazard ratio was not appropriate, and concluded there was no consistent association between milk consumption and all-cause or cause-specific mortality. [5] [5] [5]

The one intervention that can be randomised here — supplements — has been tested enough for a national body to state a position.

The United States Preventive Services Task Force recommends against daily supplementation with 400 IU or less of vitamin D and 1000 mg or less of calcium for the primary prevention of fractures in community-dwelling postmenopausal women, and found adequate evidence that such supplementation increases the incidence of kidney stones. [6] [6]

The same recommendation states that the evidence is insufficient to assess the balance of benefits and harms of vitamin D and calcium supplementation, alone or combined, in community-dwelling asymptomatic men and premenopausal women, and that the recommendations do not apply to people with a history of osteoporotic fracture, an increased risk of falls, or a diagnosis of osteoporosis or vitamin D deficiency. [6] [6]

None of this says milk is harmful or that calcium does not matter. It says that the sentence "milk is a good source of calcium, so drinking it strengthens bones" contains two claims, and only the first one is supported by what has been measured.

What this section does not show

Food and supplements are not one thing

The reviews separate calcium from food, which was not associated with fracture, from calcium supplements, where the evidence was weak and inconsistent. This section does not add them together.

One cohort of one population

The Swedish milk finding is a single cohort in one country, and its own authors call for a cautious reading because an observational design carries residual confounding and reverse causation.

Not a reason to avoid milk

Nothing here says milk is harmful and nothing here says to stop eating dairy. The strongest single trial result in this section is about supplements rather than about food.

Who the evidence excludes

The fracture trials were in people over 50, and the recommendation quoted does not apply to anyone with a history of osteoporotic fracture, an increased risk of falls, or a diagnosis of osteoporosis or vitamin D deficiency.

All twelve elements

The entry's full limits block covers the dates, the study designs, who was and was not studied, the comparators, the adjustment sets, the uncertainty, the counter-signals and what we did not check. Read it on the entry's first page.

This page is general information about published research. It is not medical advice, and it is not a substitute for advice from a qualified health professional. No clinician-patient relationship exists, and we do not know your diet, your medications, your test results, your medical conditions or your history. Talk to a health professional before changing your diet if you are pregnant or breastfeeding, feeding an infant or child, over 65, taking medication, living with a medical condition, or if you have been diagnosed with a nutrient deficiency or have a history of disordered eating. The evidence described is about groups and diets, not about you, and not about any product listed on this site. If you are unwell, contact a health professional; in an emergency, call 911. No clinician reviewed this entry. It is a compilation of published sources by this site.

Sources for this section

Every numbered sentence above was checked against the source with that number on the date shown. The number links to the entry in this list, and the entry's first page lists every source it cites.

1. Calcium intake and risk of fracture: systematic review. The BMJ. systematic review. Open the source ↗
   Checked 19 September 2026. Backs 3 sentences in this section.
2. Calcium intake and bone mineral density: systematic review and meta-analysis. The BMJ. systematic review and meta-analysis. Open the source ↗
   Checked 19 September 2026. Backs 1 sentence in this section.
3. Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study. BMC Medicine. prospective cohort study. Open the source ↗
   Checked 19 September 2026. Backs 2 sentences in this section.
4. Milk intake and risk of mortality and fractures in women and men: cohort studies. The BMJ. prospective cohort studies. Open the source ↗
   Checked 19 September 2026. Backs 1 sentence in this section.
5. Milk Consumption and Mortality from All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis. Nutrients. systematic review and meta-analysis. Open the source ↗
   Checked 19 September 2026. Backs 1 sentence in this section.
6. Vitamin D, Calcium, or Combined Supplementation for the Primary Prevention of Fractures in Community-Dwelling Adults: US Preventive Services Task Force Recommendation Statement. JAMA. recommendation statement. Open the source ↗
   Checked 19 September 2026. Backs 2 sentences in this section.