How much calcium is really in milk?
Calcium is an abundant nutrient in your body – with 99% of that calcium stored in your bones and teeth.
Despite this concentration in the bones and teeth, calcium is used throughout your body. It is involved in bone health, muscle function, blood clotting, nerve transmission, cell signals and hormone release.
Your body gets calcium from food, but it can also draw calcium from within your own body. If you do not consume enough calcium in your diet, your body will pull calcium from your bones. That’s why it’s vital to consume foods rich in calcium to help protect your bones.
What’s my recommended daily intake of calcium?
The recommended daily intake (RDI) of calcium in New Zealand is:
| Age Group | Recommended daily intake (RDI) - calcium (mg/day) |
|---|---|
| Children aged between 1 and 3 years old | 500 |
| Children aged 4 - 8 | 700 |
| Children aged 9 - 11 Women aged 19 - 50 Med aged 19 - 70 |
1,000 |
| Children aged 12 - 18 Women aged 50+ Men aged 70+ |
1,300 |
There are two times in life when additional calcium is recommended. First is in our teenage years, when our bones are rapidly growing and developing. We reach our peak bone mass by 30 years, and a higher bone mass at this time reduces the risk of osteoporosis in later life. Higher bone density in general can also reduce the risk of sarcopenia as we age.
It’s in these later years of our lives when we once again have a higher calcium requirement. Post-menopausal women and men over 70 continue to experience bone and muscle loss, so additional calcium may be needed to help maintain bone density.
Inadequate calcium consumption is widespread
Despite the benefits of a diet rich in calcium, a metanalysis of data from 74 countries worldwide found that:
- Many countries in Asia have an average dietary calcium intake below 500mg per day – less than half the recommended daily intake for adults.
- Most countries in Africa and South America have low calcium intake of between 400 and 700mg/day.
- Only Northern European countries have national calcium intakes greater than 1,000mg/day.
This is supported by a recent paper that analysed global dietary intake data to show widespread inadequate micronutrient intakes, with 66% of the global population not consuming enough calcium.
What about here in Aotearoa?
- A 2020 study found that 63% of adolescent men and 85% of adolescent women had inadequate calcium intakes.
- The earlier New Zealand Adult Nutrition Study found that 59% of adults had inadequate calcium intake, particularly seniors (both male and female) and female teenagers.
Where do most people get their calcium from?
Dairy products are the richest source of calcium. For example, one 250ml glass of whole milk has 291mg of calcium, which is almost third of an adult’s RDI. A 150g pottle of plain unsweetened yoghurt contains 240mg, or over 20% of the adult RDI. In addition, dairy products have both high calcium density and a high calcium bioavailability of around 30%. Few other foods can compete on these measures. Calcium fortified plant-based beverages, for instance, have calcium bioavailability below 5%.
In both the New Zealand studies listed above, the number one source of calcium in our diets for New Zealanders was milk. For adults, milk contributed 26.8% of their calcium, with bread the next greatest source at just 9.9%. Cheese was fourth, contributing 7.7% of adult calcium intake, with other dairy products sixth at 5.8%.
Other dairy products are also good sources of calcium:
- Yoghurt: 240mg in a 150g pottle (24% of RDI)
- Cottage cheese: 27mg in a 45g serve (3% of RDI)
- Edam cheese: 376mg in a 40g serve (38% of RDI)
- Sour cream: 23mg in a 25g serve (2% of RDI)
- Milk: 291 mg per 250ml serve (29% of RDI)
Consuming calcium rich foods is vital to help protect your bones and support your ongoing health and wellbeing - and calcium rich milk and dairy products are an easy and delicious way to achieve your recommended daily intake.