Calcium-A Requirement for Growing Bones

Recent medical news has highlighted the growing problems of osteoporosis and inadequate calcium intake. Unfortunately for adults, it is usually too little, too late. The need for increased calcium in the diet begins very early in life-especially the preteen years. In the United States, children’s milk/dairy intake has decreased and so the amount of calcium that is absorbed from their diets has too. Children with diets deficient in calcium will be vulnerable to osteoporosis later in life.

Calcium intake for children is most important to store as much calcium in the bone as possible to minimize loss over the later years. Eating or drinking the recommended amount of calcium-containing food (not just milk with cereal) is the most important way to store this nutrient.

To attain the above goals, most children need to increase the amount of calcium they eat or drink on a daily basis to meet the daily recommended requirements.

What is calcium?

Calcium is a mineral that many parts of your body (like bones, teeth, muscles, blood) need. Its main job is to build strong bones and teeth, which contain 99% of your body’s calcium. Bones are the bank for calcium. Calcium helps the muscles contract and also aids in controlling blood pressure.

What is osteoporosis?

Osteoporosis is a condition that features loss of the normal density of bone. Osteoporosis leads to abnormally porous bone that is more compressible like a sponge than dense like a brick. This disorder of the skeleton weakens the bone leading to an increase in the risk of a bone fracture. Normal bone is composed of protein, collagen, and calcium. Bones that are affected by osteoporosis can fracture with only a minor fall or injury that normally would not cause a bone fracture.  

How does my child store calcium? Can my child be more vulnerable to osteoporosis later if they do not get enough calcium in their diet today?

When your child is roughly between the ages of 9-18 years, his/her body can deposit calcium in the “bone bank” by increasing bone density. Bone density is a measure of how thick bones are. Bones with higher density are stronger and less apt to break as the body ages. Usually around age 18, the body loses the ability to bank calcium- this is the peak bone density. This means that bones are as dense or packed with calcium as they will get-FOR LIFE! After age 18, your body mainly withdraws calcium from your bone bank. Osteoporosis may develop if your body withdraws too much calcium. Osteoporosis is a disease that can make bones so fragile that they can break from the stress of just bending over.  

What else does my child need besides calcium?

Physical activity is very important. Frequent, weight-bearing exercise activities-running, jumping, playing tennis, basketball, soccer, etc help your child build healthy bones. Biking and swimming actually do not help. Vitamin D is also important. Sources of Vitamin D include sunlight, milk and other dairy products, cereals (check the label), and multivitamins.

How much calcium does my child need?

Recommended calcium intake for children ages 4 to 8
While there are no formal guidelines for prepubertal children, calcium requirements for children 4 to 8 years of age are estimated to be about 800 mg/day. This requirement is easily achieved by drinking three 8-oz glasses of milk per day, each containing 300 mg of calcium. Milk alternatives made from soy and rice are quite acceptable if they are vitamin and calcium fortified to match the nutritional content of milk.

For more reticent children, orange juice is an alternative, although it is less optimal as it contains neither the supplemental Vitamin D (a requirement for calcium absorption by the body) nor the protein and fat that milk does. A multivitamin may help in this case, and making sure that the child has enough protein and fat in the diet.

Unfortunately, this young age group also seems to retain less calcium in their bones than pubertal children do, which makes getting sufficient calcium intake critical.

Recommended calcium intake for children ages 9 to 18
Starting at age 9 the recommended adequate calcium intake increases to 1300 mg per day for the next 9 years. A survey in 1994 by the US Department of Agriculture found that there is a serious deficiency in the amount of calcium most children are getting:

• Children ages 9 to 13 averaged less than 1000 mg per day, with girls getting about 800 mg.
• In teens ages 14 to 18, daily intake of calcium in boys increased to just over 1000 mg per day, and for girls decreased to less than 700 mg per day.

According to this study, the vast majority of girls actually were taking in only a little more than half the recommended amount of calcium per day. Females especially may experience more long-term calcium wasting as a result of bearing children and hormonal fluctuations.

 

What are good sources of dietary calcium?

Milk, yogurt, cheeses, cottage cheese are generally great sources of calcium. Flavored milks such as chocolate, strawberry have as much calcium as plain milk but with more calories. Dark green, leafy vegetables such as kale and turnip greens are low in calories and high in calcium. Broccoli, tofu, chickpeas, lentils, split peas, and salmon are great sources, too.  Spinach is not a good source of calcium. Calcium fortified juices and cereals can help boost the calcium in the diet, but limit your child to 8-12 ounces (1^1/2 cups of juice/day).

There are ways to boost calcium in the diet of an older child/teen:

• Boost calcium in salads with beans, cheese, broccoli, tofu or almonds (if not allergic)
• Give yogurt as a light meal or snack. Add fresh fruit or mix in pancakes, salad dressings, dips and sauces
• Create special drinks with milk or yogurt-make shakes or smoothies
• Waffles and cereal fortified with calcium are great for breakfast!
• Add nonfat dried milk (1 tbsp=85 mg of calcium) to pancakes, waffles, cream soups, mashed potatoes, cooked cereals.

What about calcium supplements?

If diet is deficient in necessary calcium, a supplement should be given. Many multivitamins for children contain calcium, but check the label, some do not. Some multivitamins contain between 100-200 mg of Calcium. Check with your medical provider if you have questions as to the amount or type of supplement you should administer to your child.

What decreases my child’s calcium intake?

Drinking a lot of soda! Soda pop contains phosphorus which may interfere with how your body handles calcium. Certain diets such as a vegan diet or a vegetarian diet may exclude dairy products-check with your medical provider. Caffeine may also interfere with calcium intake.

How do I read these confusing food labels?

Food labels list the amount of calcium in a serving as % Daily Value not as milligrams (mg). 100% of the Daily Value=1000 mg of calcium/day. To find out how many milligrams of calcium are in a serving, place a “0” at the end of the number listed for a daily value. For example a serving of calcium fortified orange juice might list the amount of calcium as 30% of the Daily Value = 300 mg Calcium.

If you are reading this as a parent and it concerns you, it is not too late. Even small dietary increases in calcium can lead to significant improvement in bone mineral content.