You’ve no doubt heard about the importance of calcium and healthy bones.
But is there a danger in consuming too much calcium? How much is enough? Could supplements be doing more harm than good?
It might come as a surprise, but most people reach peak bone mass between the age of 25-30 years old. After this time, the bone mass starts to decline as bone is broken down at a faster rate than new bone tissue is produced. Women typically have less bone mass than men and the acceleration of bone loss in women occurs post-menopause due to declining oestrogen levels. When it comes to bone health, it is crucial to take a preventative approach and ensure adequate nutrition that supports bone health. By doing this you can minimise the risk of developing osteoporosis and reduce the risk of bone fractures in later years.
A Balancing Act
Calcium is an essential mineral and is the building block of teeth and bones. The skeleton acts as the reservoir of calcium within the body. Adequate calcium levels in the blood are necessary to maintain healthy nerve and muscle function. Calcium levels in the blood are tightly controlled by the parathyroid gland. If your intake of calcium is not sufficient, then the body will respond by taking the calcium it needs from your bones to ensure blood calcium levels stay in the optimum range.
Our calcium requirements change depending on our age. Teenagers require more calcium as they are going through a stage of rapid growth. As we reach our 70’s the ability to absorb calcium also tends to decrease and hence higher amounts are required. The recommended daily intake (RDI) of calcium for adults from dietary and supplement sources is.
- Women 50 and younger: 1,000 mg per day
- Men 70 and younger: 1,000 mg per day
- Women over 50: 1,200 mg per day
- Men over 70: 1,200 mg per day
Calcium is found in a variety of food sources such as milk, yoghurt, cheese, tofu, broccoli, tinned salmon and sardines, almonds, poppy, sesame, and chia seeds. Some examples of calcium content in foods to help you reach your daily target.
- 250ml of full cream milk or 200g pot of yoghurt = 300mg calcium
- 85g tinned salmon with bones = 181mg
- ½ cup tofu (made with calcium salt) = 253mg
- 1 tbsp tahini (made from sesame seeds) = 63mg
- 1 cup cooked broccoli = 45mg
What supplements should I take?
To determine how much calcium you are getting from supplements, it is important to look not only at the form of calcium (which may determine its absorption) but also the equivalent amount of calcium that it contains. Some types of calcium found in supplements are:
Calcium carbonate: commonly used and inexpensive. It is best taken with food for improved absorption. It is higher in elemental calcium however requires adequate levels of stomach acid (HCL) for absorption.
Calcium citrate: well-absorbed form and can be taken with or without food. It is recommended for those with low stomach acid, such as people taking medications for acid reflux and having malabsorption issues such as inflammatory bowel disease.
Hydroxyapatite: a calcium phosphate compound naturally found in bones and teeth of humans and animals.
Aquamin® Forte: is a natural calcium-rich marine-sourced multi-mineral derived from the cytoskeleton of red algal Lithothamnion spp.
A team effort for healthy bones
So, you think you’ve got your calcium intake covered through a combination of diet and/or supplements? That’s a big tick to supporting your bone health, but there are some important nutrients you need that work in combination with calcium to ensure it gets to where it is required in your bones and teeth.
Adequate vitamin D is essential in ensuring that calcium is absorbed from the small intestine into the bloodstream. It works in combination with the parathyroid gland to regulate calcium levels in the blood.
Vitamin K2 is a more recent addition to the bone-building team. It activates two proteins called osteocalcin and MGP (matrix Gla protein) which work to steer calcium from the bloodstream into the bones and teeth and away from places where it shouldn’t be, like your arteries. This helps to keep the blood vessel walls flexible and supports cardiovascular health.
Exercise, particularly weight-bearing exercise is also an important component of supporting healthy bone density.
Too much of a good thing?
Whilst calcium is a crucial nutrient for our health, there are also possible risks with consuming too much. Research to date has provided conflicting results in relation to calcium supplementation and increased risk of cardiovascular disease and prostate cancer.
It is best to avoid excessive amounts of calcium and stick to the recommended daily intake of calcium from both dietary and food sources relevant to your age and sex (as discussed above). The maximum level of calcium from both dietary and supplement sources should not exceed 2,500mg/day if you are under 50 years old. If you are over 50, the maximum limit is 2,000mg/day.
Typically, calcium supplementation of 500 to 600 mg/day is safe and effective for supporting bone health in people who don’t get enough calcium from their diet. If you have any concerns about calcium supplements, talk to your doctor, pharmacist, or other healthcare professionals. Always follow the label and take any supplements as directed.
References
Mayo Clinic (2022) Calcium and calcium supplements: Achieving the right balance - Mayo Clinic; accessed from <Calcium and calcium supplements: Achieving the right balance - Mayo Clinic>
National Institutes of Health (NIH) (2022) Calcium fact sheet for health professionals- National Institutes of Health Office of Dietary Supplements; accessed from <Calcium - Health Professional Fact Sheet (nih.gov)>
Nutrient reference values for Australia and New Zealand (2006)Calcium | Eat For Health – National Health and Medical Research Council (NHMRC); accessed from <Calcium | Eat For Health
