Information on Why You Need Calcium
We all know you need calcium for strong bones and teeth. What you may not know is that calcium is required for every cell of the body to function in a healthy way. Besides acting as a cellular cement for bones, calcium is used by nerves and muscles, and it also contributes to proper blood clotting. Here’s an overview of where and why you need calcium:
You need calcium for healthy bones and teeth
Just as lime is necessary for strong concrete, calcium is needed for strong bones. Calcium is continually deposited into multiplying bone cells, like the cement that holds together the particles of stone and sand in a chunk of concrete. The stronger the bone development during childhood, the healthier those bones will be in adulthood. That is, the stronger the foundation, the sturdier the eventual building.
During adolescence, bones grow rapidly, so teens need a lot of calcium in their diet. Once a person reaches full growth, calcium needs stabilize, but there are periods when calcium needs increase, such as during pregnancy, lactation, and healing from injuries. In old age, the bones begin to lose some of their sturdiness (this is called osteoporosis or “fragile bones”). There are a variety of reasons for this, some hormonal and some related to the fact that calcium absorption lessens in elderly intestines. Also, certain medications decrease the body’s ability to absorb calcium, including antacids . Senior citizens need to be particularly conscious about the level of calcium in their diet and about which medications interfere with calcium absorption.
It’s best not to wait until you’re fifty-something to start preventing osteoporosis. Building stronger bones with a calcium-rich diet and weight-bearing exercise in your twenties and thirties is more likely to prevent osteoporosis than preventive measures in your fifties.
Other functions of calcium
Besides promoting healthy tooth enamel, calcium helps muscles. Muscles can cramp, and heart muscles can even fail, if these muscles are not supplied with just the right amount of calcium. Nerve impulses, the transmission of information between nerve fibers, will not function properly without just the right amount of calcium. For example, muscles twitch (called tetany) when the calcium supply to neuromuscular cells is insufficient. Calcium is one of the most vital minerals for optimal functioning of your entire body.
How does calcium work
As with other minerals, the body has a marvelous system for keeping the concentration of calcium in the blood and tissues just right. This is needed because if calcium concentrations fall too low or get too high, certain organs will fail to function. The first checkpoint is in the intestines. If you eat too much calcium or already have enough calcium in your blood, the intestines simply absorb less of the calcium in the food you eat. If your body needs calcium, the intestines absorb more. Bones are the second checkpoint. If you don’t get enough calcium in your diet, your body may borrow what it needs from your bones. This works for a time, yet continued withdrawals of calcium from the bone bank can lead to osteoporosis. A hormone called parathyroid oversees all this calcium activity like a vigilant bank manager, keeping the calcium concentration just right. When calcium levels fall, this hormone stimulates vitamin D to increase absorption of calcium from the intestines and to release calcium from the bone bank until a proper balance is restored.
You need different calcium levels at different life stages
While the body at any age needs calcium, there are stages in a person’s life when calcium requirements increase. Here are the daily requirements at various stages in your life:
Stages Equivalent to Daily Calcium Intake
- Pregnancy: 1,500-2,000 mg. a day
- Lactation: 1,200-1,500 mg. a day
- Infants (birth to one year): 400 to 600 mg.
- Children (1 to 10): 800 mg.
- Preteens and teens: 1,200-1,500 mg.
- Adults: 1,200 mg.
- Seniors: 1,500 mg. a day
What are the Best Dairy and Non-Dairy Sources of Calcium?
| Best Dairy Sources | mg. | Best Non-Dairy Sources | mg. |
|---|---|---|---|
| Yogurt nonfat, plain (1 cup) | 450 | Sardines (3 oz) | 371 |
| Yogurt, lowfat, plain (1 cup) | 400 | Orange juice, calcium-fortified (1 cup) | 300 |
| Yogurt, nonfat, fruit (1 cup) | 300 | Sesame seeds (1 ounce) | 280 |
| Parmesan cheese (1 ounce) | 336 | Tofu (3 oz) | 190 |
| Milk, lowfat (1 cup) | 300 | Salmon (3 oz, canned) | 180 |
| Romano cheese (1 ounce) | 302 | Collards (1/2 cup, chopped) | 180 |
| Cheddar cheese (1 ounce) | 200 | Rhubarb (1/2 cup) | 174 |
| Cottage cheese (1 cup) | 155 | Blackstrap molasses (1 tbsp.) | 172 |
| Amaranth flour (1/2 cup) | 150 | ||
| Spinach (1/2 cup, canned) | 136 | ||
| Figs (5) | 135 | ||
| Artichoke (1 med.) | 135 | ||
| Soybean nuts (1/4 cup) | 116 | ||
| Turnip greens (1/2 cup, chopped) | 100 | ||
| Cereal, calcium-fortified (1/2 cup) | 100-200 | ||
| Kale (1/2 cup, chopped) | 90 | ||
| Almond butter (2 tbsp.) | 86 | ||
| Beet greens (1/2 cup, boiled) | 82 | ||
| Almonds (1 ounce) | 80 | ||
| Bok Choy (Chinese cabbage) (1/2 cup) | 79 | ||
| Okra (1/2 cup) | 77 | ||
| Tempeh (1/2 cup) | 77 | ||
| Beans (1/2 cup, baked) | 75 | ||
| Papaya (1 medium) | 73 | ||
| Orange (1 medium) | 50 | ||
| Broccoli (1/2 cup, chopped) | 47 |
Check out these other calcium-related articles by Dr. Sears:
Does My Toddler Need Cow’s Milk?
Dr. Sears, or Dr. Bill as his “little patients” call him, has been advising busy parents on how to raise healthier families for over 40 years. He received his medical training at Harvard Medical School’s Children’s Hospital in Boston and The Hospital for Sick Children in Toronto, the world’s largest children’s hospital, where he was associate ward chief of the newborn intensive care unit before serving as the chief of pediatrics at Toronto Western Hospital, a teaching hospital of the University of Toronto. He has served as a professor of pediatrics at the University of Toronto, University of South Carolina, University of Southern California School of Medicine, and University of California: Irvine. As a father of 8 children, he coached Little League sports for 20 years, and together with his wife Martha has written more than 40 best-selling books and countless articles on nutrition, parenting, and healthy aging. He serves as a health consultant for magazines, TV, radio and other media, and his AskDrSears.com website is one of the most popular health and parenting sites. Dr. Sears has appeared on over 100 television programs, including 20/20, Good Morning America, Oprah, Today, The View, and Dr. Phil, and was featured on the cover of TIME Magazine in May 2012. He is noted for his science-made-simple-and-fun approach to family health.