Calcium

Ensuring that we feed our kids a diet high in calcium-rich foods means setting them up for a lifetime of strong bones and teeth. Thankfully, in addition to milk, there are many tasty ways to increase their calcium intake.

Calcium is required for the normal development and maintenance of the skeleton, as well as for the proper functioning of neuromuscular and cardiac function. It is stored in the teeth and bones where it provides structure and strength. Bone density is determined by calcium, and bones are the storehouses of calcium in the body.

The demand for calcium when we are young is high, both for growth and bone maintenance. Indeed, from birth through adolescence, our bone mass increases at a fast pace and an appropriate intake is required to ensure peak bone mass is reached. This continuous building of the calcium in our bones determines the strength of our bones for the future. Our bone mass then remains stable until about age 50 in men and until the menopause for women, when it begins to decrease.

The RDI (Recommended Daily Intake) varies depending on age.

  • For babies, it starts from around 200mg for a newborn to 270mg for a 1-year-old daily.
  • Children aged 1- to 3-years-old need 500mg/day.
  • Children aged 4- to 8-years-old need 700mg/day.
  • Children aged 9- to 11-years-old need 1000mg/day.
  • Children aged 12- to 18-years-old need 1300mg/day.
  • The RDI for men and women up to 50-years-old is 1000mg/day.

There are also specific times when women may have increased calcium requirements, being:

  • Teenage pregnancy – in this case, it is essential for the teenage mum to ensure a higher supply of dietary calcium to cover her own needs and those of the growing baby. (However, there is no need for most fully-grown women to increase their calcium intake during pregnancy, because less calcium is excreted, while at the same time its absorption rate rises, thus conserving supplies.)
  • Women over 50 – one in two women will develop osteoporosis. During menopause, women produce much less estrogen, which can accelerate the loss of calcium and increase the risk of brittle bones.

Only about 40% of the calcium that we eat is absorbed. It should be kept in mind that Vitamin D is needed to absorb calcium properly, so it is important to have an appropriate amount of vitamin D in our diets. Here again, a balanced diet comes into the picture. Absorption can also be affected by certain foods. Essential fatty acids may help absorption, and regular exercise helps maintain bone mass. Foods high in insoluble fibre, such as wheat bran and whole grains, can hinder absorption of calcium (if taken at the same time) and so can oxalates, found in spinach, rhubarb, chocolate and beetroot, high sodium and protein intake, and the tannin in tea and coffee. So if you drink tea or coffee, it is a good idea to leave a gap between your drink and your meal where possible.

Any kind of bony structure in our body can be weakened due to calcium deficiency. Indeed when calcium is lost from bones, the bones become thin, brittle and break easily. In severe cases, fractures occur following only slight knocks or normal activities such as lifting or bending. Low intakes of calcium have been associated with a condition of low bone density called osteoporosis which is quite common in western cultures and which often results in bone fracture. Other symptoms of deficiency include muscle cramps and weakness.

Calcium supplements can be used to prevent and to treat calcium deficiencies. Most experts recommend that no more than 600mg should be taken at a time because the percentage of calcium absorbed decreases as the amount of calcium in the supplement increases. Vitamin D is often added to calcium supplements and it is recommended to take them with food to help absorption.

Excessively high levels of calcium in the blood impair kidney function and, in addition to high phosphorus levels in the blood, have been associated with the development of calcifications in the heart, blood vessels, lungs and around the joints. However, this rarely results from dietary or supplemental calcium intake and is most commonly associated with conditions such as parathyroidism, advanced cases of cancer or excessive intakes of vitamin D from supplements.

A healthy diet involves a good amount of calcium-rich foods. Dairy products, such as milk and cheese, are a well-known source of calcium. Some individuals are allergic to dairy products and even more people are lactose-intolerant, leaving them unable to consume non-fermented dairy products. Fortunately, many good alternative sources of calcium exist. Smaller amounts of calcium can be found in bony fish, green leafy vegetables and certain nuts, fortified soy beverages and breakfast cereals.

Foods that are good sources of calcium include:

  • Milk
  • Yoghurt
  • Cheese, especially Parmesan, Gruyere, Cheddar and many other hard cheeses
  • Powdered milk
  • Feta cheese
  • Mozzarella cheese
  • Tofu
  • Sardines (including bones)
  • Almonds
  • Soy beans
  • Figs
  • Green beans
  • Spinach
  • Broccoli
  • Chickpeas

This recipe is a great way to serve fish to children and to keep their calcium intake up. Younger children are more likely to eat fish when it is mixed with a variety of other favourite ingredients such as eggs, cheese and potatoes. This dish makes a warming and hearty dinner and will be particularly appreciated on a cool evening. The mushroom soup may be substituted for another flavour of your choice. Although I have used fresh green beans in this recipe, out of season you may use another calcium-rich seasonal vegetable as a substitute.

Fish pie

Serves 4

Ingredients

3 potatoes

300g fresh green beans

½ bunch parsley

450g red cod

1 tablespoon extra-virgin olive oil

2 hard-boiled eggs

150g condensed mushroom soup

150ml milk

100g cheddar cheese

1 tablespoon dill

1 lemon

2 tablespoons breadcrumbs

Directions

Preheat oven to 180ºC (350ºF). Grease a deep ovenproof dish. Peel the potatoes and cook for 15 minutes in a steamer. Cut both ends off the beans and cook for 10 minutes in a steamer. Wash and finely chop the parsley.

Cook the fish in a frying pan with the olive oil, lemon juice and dill. Set aside on a plate, crumb and make sure to discard any bone. Shell and slice the eggs. Slice the potatoes.

Place the sliced potatoes in the prepared dish. Cover with the crumbed fish and half the chopped parsley. Top with the green beans and slices of hard-boiled eggs. Mix the condensed soup with the milk and use to cover the fish and vegetables. Sprinkle with the grated cheese, remaining parsley and breadcrumbs.

Fan bake for 30 minutes. Serve hot.

 

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