Dietitians agree that it’s best to obtain your calcium from food. But when you can’t (or don’t want to) drink all that milk, calcium supplements can be useful – at least, some of them can, says HFG nutrition director Catherine Saxelby.
Did you know that the RDI for calcium has been revised? Until 2006, it was advised that we get 800mg a day – obtained easily enough through three serves of dairy, such as a glass of milk, a tub of yoghurt and a thick slice of cheddar cheese. But since then, the goal posts have shifted: recommendations for adults are now 1000mg a day, while teenagers, women over 50 and men over 70 require a hefty 1300mg. That means we need four or five serves of dairy daily!
It seems most of us don’t get nearly enough calcium. In fact, according to the last National Nutrition Survey (conducted in 1995), the average calcium intake for Australian women was 750mg a day and 950mg for men, with more recent research suggesting calcium intake has declined even further since then – to just 400mg.
So calcium supplements can play an instrumental role in keeping you healthy, particularly if you don’t eat many or any dairy foods, or are at risk of osteoporosis. Even if this doesn’t sound like you, calcium supplements can still be a good idea – you can use them to ‘top up’ your daily calcium needs, bridging the gap between what you get from food and what’s recommended. Taking a supplement that provides 500–600mg pure calcium per tablet each day, in combination with the average 400mg intake from food, means you will meet your RDI. However – there’s a huge range in the quality of calcium supplements, and some really aren’t worth the money.
To make sure you’re not getting ripped off, there’s a few things to keep in mind:
Reading the label
Labels can be a little confusing as they often list the quantity of the calcium compound, such as calcium carbonate (the most common form of calcium), calcium gluconate, calcium orotate, calcium citrate or calcium amino acid chelate – and that’s not the same as pure calcium. A tablet with 1500mg of calcium carbonate, for example, provides only 600mg of the good stuff. Only buy tablets that state the amount of pure calcium.
How much elemental or ‘pure calcium’ are you actually getting from each tablet? Make sure you’re getting 200mg or more of pure calcium – otherwise you’re wasting your money. Many smaller brands have such a small amount, they don’t noticeably contribute to your intake. For example, supplements with 650mg calcium gluconate only supply 60mg of pure calcium.
Unless you get outdoors several times a week without sunscreen on, you’re probably mildly deficient in vitamin D, which is essential for the absorption of calcium. So look for a combined supplement, with 5mcg (or 200IU) of cholecalciferol (the chemical name for vitamin D) or vitamin D3. The RDI for adults aged 19 to 50 is 5mcg (or 200IU), for ages 51 to 70 is 10mcg (400IU), and for anyone over 70 is 15mcg (600IU). As you can see, vitamin D becomes more critical as we age.
Ideally, your supplement should include additional minerals, such as magnesium and potassium. Potassium is believed to help preserve bone calcium, while magnesium helps transport potassium into the bones and is essential for the absorption and metabolism of calcium.
So are they worth buying?
Yes, but don’t exceed the recommended amount! A recent study of older women who took daily supplements of 1000mg of calcium to protect their bones displayed a significantly higher risk of heart attack than those who didn’t take the supplements. So until we know more, the best advice is to get the majority of your daily calcium from food and drink, and use supplements to make up the difference.
Are you at risk of osteoporosis?
We should all be getting more calcium, but a supplement is extra important for those particularly at risk of osteoporosis:
Anyone with a family history of osteoporosis or bone fractures at an early age.
Models, ballet dancers, elite athletes and anorexia sufferers who had a low body weight in their late teens and early 20s.
Women who have gone through menopause or are currently on hormone replacement therapy (HRT).
Anyone taking medications to halt osteoporosis.
Why take calcium at night?
It’s recommended that we take calcium supplements just before bed, as calcium uptake by bones peaks during the night. But they should be kept separate from other medications, as calcium may decrease their absorption. If you’re taking tetracycline antibiotics (a common form of antibiotics), bisphosphonates (drugs to treat osteoporosis) or thyroid hormone, take your calcium at least two hours later and also consult with your doctor. This is also good advice for those taking iron tablets and antacids that contain aluminium.
Finally, if you are taking a supplement containing calcium carbonate, take it with food – it’s absorbed much better that way. (However, supplements containing calcium citrate, calcium lactate or calcium gluconate can be taken with or without food).
Hard to swallow
Q: I find calcium tablets really large in size and hard to swallow. Can I take the effervescent types instead?
A: Chewable calcium tablets are a better option. Effervescent tablets contain sodium bicarbonate (to give it that fizz), which adds salt to your diet. Besides, cutting back on salt can benefit bones: every 2000mg of sodium (the average daily intake) removed by the kidneys in urine takes 60mg of calcium with it. Over 10 years, this removes 150–200g of calcium – almost 15 per cent of the skeleton.
Healthy Food Guide recommends
Caltrate 600mg with Vitamin D Contains 1500mg calcium carbonate, which gives you 600mg of pure calcium per tablet. This also contains 5mcg vitamin D, which assists with your body’s absorption of calcium, so it’s useful if you don’t get enough sunshine.
Herron Calcium Plus Contains 1500mg calcium carbonate (600mg pure calcium) and 5mcg vitamin D. It also contains other important minerals, such as magnesium and boron for skeletal development and repair.
Calcia Calcium EasyChew Tablets Contain 1250mg calcium carbonate (500mg pure calcium). Available in orange flavour, they’re useful for those who have trouble swallowing conventional calcium supplements, which can be quite large.
Nature’s Own Calcium & Magnesium with vitamin D3 Has 500mg calcium amino acid chelate and 350mg calcium carbonate, equating to 250mg pure calcium (or when taken as directed, 2–3 times a day, this equates to 500–750mg pure calcium). It also contains magnesium and 5mcg vitamin D.
Blackmores Total Calcium Contains 300mg calcium citrate, 325mg calcium phosphate and 200mg calcium amino acid chelate, which equates to 229mg pure calcium per tablet (or when taken as directed, 2–3 times a day, around 458–687mg calcium). This tablet also contains 5mcg vitamin D, plus magnesium and zinc, which is important for bone formation.
*Some supplements give their vitamin D content in International Units (IU). 200IU is equivalent to 5 micrograms (mcg). The adequate intake for vitamin D is 5mcg (or 200IU) a day for adults up to 50 years, then 10mcg (400IU) for 50 to 70, and 15mcg (600IU) for anyone over 70.