Calcium Intake Levels: What Official Bodies Say for Different Ages and Countries

What the question means

"How much calcium per day" has no single answer. Different health bodies publish different reference numbers for different groups, and each number answers a slightly different question. This page lists what the sources we read say. It is information, not a personal plan; a clinician or dietitian can look at your diet, health and medicines.

How the sources define the terms

• RDA (Recommended Dietary Allowance): the average daily intake enough to meet the needs of nearly all (97% to 98%) healthy people. [1]
• AI (Adequate Intake): set when there is not enough evidence to develop an RDA; it is thought to ensure enough nutrition. [1]
• UL (Tolerable Upper Intake Level): Health Canada describes it as the highest average daily intake level likely to pose no risk of adverse health effects, and says it is not a recommended level of intake. [2]
• PRI (Population Reference Intake): the term EFSA uses for the EU's reference values, alongside Average Requirements and Adequate Intakes. [3]

These values are for planning and judging the intake of healthy people. [1]

United States and Canada: reference intakes

MedlinePlus lists these values, which it attributes to the National Academies. The amounts count calcium from food and supplements together. [1]

Health Canada's table of reference values for elements lists the same calcium RDA and AI figures, with upper limits as below. [4]

Upper limits

The EU committee said data were insufficient to set an upper level for children and adolescents. [5] MedlinePlus describes the US safe-intake amounts in similar words: 2,500 mg for adults 19 to 50, 2,000 mg for adults over 50, and 2,500 to 3,000 mg for children and adolescents. [1] The NHS says 1,500 mg or less a day is unlikely to cause harm and that more than 1,500 mg could cause stomach pain and diarrhea. [6]

UK and EU reference values

• NHS (UK): adults 19 to 64 and over need 700 mg a day; the page was last reviewed in 2020. [6]
• EFSA (EU), reference values (Population Reference Intakes and Adequate Intakes) in a 2017 summary table: 450 mg for ages 1 to 3, 800 mg for ages 4 to 10, 1,150 mg for ages 11 to 17, 1,000 mg for ages 18 to 24 and 950 mg for ages 25 and over. [3] The same table gives 1,000 and 950 mg for pregnancy and lactation by age band. [3]

Why the numbers differ

The sources set their values at different times and for different populations, and each uses its own method. We did not find, in the pages we read, a single explanation for each gap between the UK and the US figures, so we do not offer one. The practical point is that no figure is universal. Do not treat one country's number as another country's rule.

Elemental calcium, labels and units

Supplement labels list calcium in mg. MedlinePlus advises checking the Supplement Facts panel for the amount in a product. [1] Trials describe the amount as elemental calcium, for example "1000 mg of elemental calcium as calcium carbonate". [7] We did not find a compound-to-elemental conversion in the pages we read, so check the label rather than convert yourself. See Understanding minerals.