5 reasons why you must get enough calcium

Everyone knows we need calcium to build strong, dense bones in our younger years so we can prevent the crippling bone disease, osteoporosis, later in life. Osteoporosis literally means 'porous bones'. It is a thinning and weakening of the bones due to loss of mineral-containing material and it affects one in two females and one in three males over the age of 60.

This post is sponsored by HeartActive milk

HeartActive is a delicious, 99% fat free milk enriched with plant sterols, which are proven to help reduce cholesterol. Research shows that consuming plant sterols everyday in milk can reduce cholesterol by an average of 10% in three weeks. HeartActive is currently available in a 1 L carton with an extended shelf life (45 days from production) compared to 'regular' white milks with a shelf life of 14 days.

I was stunned to learn that more than 60 per cent of Australian women consume less than the recommended intake of calcium. The reason? They frequently cut out calcium-rich dairy foods in order to cut kilojoules (calories), avoid cholesterol and saturated fat, or because of a dairy intolerance – real or perceived.

Of the body's calcium, 99 per cent is stored in the bones and teeth. So clearly calcium is a key bone ingredient but so are other minerals such as phosphorus and magnesium - not forgetting that you also need vitamin D from sunlight and regular weight-bearing exercise to maintain healthy bones. However, there are 5 other biological reasons why you must get enough calcium. These are:

1. You must have calcium to make your muscles move

Muscle contraction is regulated by the level of calcium. Muscles contract and relax because of rapidly changing concentrations of calcium inside your muscle cells. Too much or too little calcium in your blood may cause muscular symptoms, such as cramps and pins and needles, due to disruption of the calcium cycle.

2. You need calcium so your blood will clot properly

Whenever you cut yourself, your body initiates a complex cascade of reactions involving platelets, enzymes, calcium and structural proteins to form clots to slow the blood flowing out from the cut. Calcium combines with Vitamin K and a protein called fibrinogen. The platelets react with fibrinogen to create fibrin, which is a mass of "tiny threads". This fibrin hardens quickly to form a scab over the wound. This is the coagulation process by which blood vessels repair an injury.

3. You need calcium to lower your blood pressure

Keeping your blood pressure within the normal levels as you get older is extremely important to your overall health, as your doctor will tell you.

Calcium has been shown to lower blood pressure in both animals and humans - something that's been known for over 50 years. US research reports that as long as calcium intake is high, people can eat a higher sodium diet with little ill effect on blood pressure – good news, as a high calcium intake can protect against salt sensitivity.

The famous DASH Diet (Dietary Approaches to Stop Hypertension) showed that by adding low fat dairy foods, such as HeartActive milk, to a diet high in fruit and vegetables, blood pressure could be reduced to levels previously only achieved with medication.

4. You need calcium for fluid balance

Calcium is a key electrolyte (a mineral that has an electric charge) as are sodium, potassium, chlorine, phosphate and magnesium. Electrolytes are in your blood, urine and body fluids. Maintaining the right balance of electrolytes helps your body's blood chemistry and ensures your fluid balance works. Calcium is found mainly in the extracellular fluids.

If the levels of calcium in the body drop too low, the parathyroid gland is stimulated to secrete parathyroid hormone. This causes an increase in both calcium and phosphate by releasing them from the reservoirs of these minerals in the bones and the teeth. (In other words you are losing bone density!) This hormone also reduces the calcium excreted by the kidneys.

5. You need calcium to combat colon cancer

The case for calcium as a protective nutrient against colon (bowel) cancer is growing. Calcium is believed to work by either binding to, or neutralising, potential cancer-causing compounds found in the bowel contents.

How much calcium

Around 800 to 1,000 mg of calcium is recommended each day, rising to a high of 1,300 mg for women after menopause when your chances of osteoporosis rise.

It's hard work reaching this Recommended Dietary Intake (RDI) and you can't beat milk along with yoghurt or cheese - packed with bio-available calcium - to get you there.

Don't forget that lactose, the natural sugar in milk and yoghurt, enhances the absorption of calcium, making milk not only one of the richest, but also one of the most readily available sources of calcium.

Standard low-fat milks have between 285 and 320 mg calcium per glass (120 mg per 100 ml) and this is the figure to look for on the label. Some speciality milks are enriched with extra calcium and offer more calcium per glass which is helpful if you're looking for calcium alone.

HeartActive milk offers 308 mg per glass along with its added plant sterols for lowering cholesterol so it's the best choice if you're seeking to eat for a healthy heart.

Your richest calcium choices

   Average values

Other ways to top up your calcium via milk

• Have lots of milk in your tea or coffee.
• Drink a glass of milk to fill you up and cut hunger.
• Add milk to your soups to finish them off – instead of cream.
• Satisfy those afternoon munchies with a fruit smoothie made with icy cold milk.

HeartActive is a delicious, 99% fat free milk enriched with plant sterols, which are proven to help reduce cholesterol. Research shows that consuming plant sterols everyday in milk can reduce cholesterol by an average of 10% in three weeks. HeartActive is currently available in a 1 L carton with an extended shelf life (45 days from production) compared to 'regular' white milks with a shelf life of 14 days.