Today I had an appointment with my dentist for a check-up and to my surprise, even I as a conscientious medical student, I was told that I had to increase the intake of calcium in my diets. Most people think that just drinking a glass of milk everyday is sufficient for their daily calcium intake. There are also people who are vegetarians who don't eat dairy products(not the lacto-vegans) and there are even some that do not touch milk.
Calcium is the most abundant mineral in the body and it accounts for 2% of our body weight. Not only is it the main building block of our bones, teeth and nails, it also helps stimulate muscle movement.
Why we need calcium?
- Calcium helps strengthen and protect the the bone.
- Calcium is needed to build your nails and the dentine and enamel of your teeth.
- Your skeleton is a living tissue and thus, it's continuously being broken down and renewed. So as your bones age, they are gradually replaced by fresh supplies of calcium and all the other necessary bone-building materials.
Where do we get calcium?
You aren't born with a store of calcium to use for bone building and maintenance, so all the calcium you need has to be taken in as part of your diet. Calcium is present in a wide range of foods, not just milk and cheese. The main sources of calcium are milk and milk products. Another good source is the small soft bones in fish such as salmon, sardines, herring and whitebait. These can safely be eaten and like all bone, contain a lot of calcium.
Other calcium-rich foods include leafy green vegetables and cereals. However, special substances in cereals, called phytates, can reduce the amount of calcium which the body can use.
Because of these absorption problems, it's best to get your calcium from a wide range of foods, instead of relying on one or two.
Here are a few examples of food containing calcium.
Cheddar chesse: 720 mg/100g
Milk (whole): 115 mg/100g
Milk (semi-skimmed): 118 mg/100g
Milk (Skimmed): 120 mg/100g
Yoghurt (plain): 190 mg/100g
Cottage Cheese: 73 mg/100g
White Bread: 110 mg/100g
Wholemeal Bread: 54 mg/100g
Canned Sardines: 550 mg/100g
Canned Salmon: 93 mg/100g
Broccoli: 40 mg/100g
Watercress: 170 mg/100g
How much calcium do we need?
Although your bones contain lots of calcium, they don't act as a store of the mineral and it can't be borrowed from them for other functions. This is why it's important to eat calcium every day, and the amount you require will depend largely on your age and health.
Children 7-10: 550 mg/day
Boys 11-18: 1 000 mg/day
Girls 11-18: 800 mg/day
Adults 19+: 700 mg/day
Pregnancy: 700 mg/day (Minimum!)
Lactation: 1 250 mg/day
If your diet doesn't include the recommended amount of calcium, you can take a calcium supplement. These are available without a need for prescriptions from pharmacies and health food shops, but consult your doctor or a pharmacist first.
Don't take more that a total of 2 000 mg (2g) of calcium per day though!
Calcium and osteoporosis
If you consistently fail to eat the recommended amount of calcium, you may be at risk from osteoporosis or brittle bone disease.
As a normal part of aging, calcium is gradually lost from bone faster than it can be replaced. The result is that bones become weaker and more brittle as you get older. Bones which have not been fed sufficient calcium to strengthen them during the first 30 years of life will then weaken more quickly.
Women are at a greater risk of osteoporosis because the female hormone oestrogen, which helps to maintain bone strength, starts declining at the menopause. Sadly, it's not possible to cure osteoporosis by increasing the amount of calcium in your diet. This means it's vital you eat enough calcium, especially in your teens and 20s, before peak bone mass is reached.
Extra tips on calcium intake
- Even as an adult, your skeleton is being replaced every 7 to 10 years. So you need to keep up your calcium intake throughout your entire life.
- If you eat a lot of meat, you may need extra calcium. High levels of protein increase calcium absorption but also increase the amount lost in urine.
- Smokers and drinkers also need to increase their daily calcium intake.
Your skeleton is a living tissue and a constant intake of calcium is needed to keep it strong and healthy.
Health File - Calcium
Wikipedia - Calcium
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