Despite ads and public health messages that try to get Americans to drink more milk, we aren't getting enough calcium. The vast majority of us don't get the recommended amount of this vital mineral. That's a real worry, because without plenty of daily calcium our bones don't grow or stay as strong as we need for the long lives we now enjoy.
But calcium alone isn't enough. We can't absorb calcium without vitamin D. That's why it's added to milk. But that's not doing the trick. About 75% of Americans, kids and adults, have low blood levels of vitamin D. Our bodies make vitamin D in response to sunlight on our skin. Our indoor lives and drinking less milk have caused levels to drop over the years. The American Academy of Pediatrics (AAP) now recommends that infants, children and teens get multivitamin drops or tablets to make sure they get at least 400 IU of vitamin D every day. They're concerned that low vitamin D levels set kids up for weak bones that break easily. It's really a lifelong issue. Older adults who are low on Vitamin D have more falls and hip fractures.
What's the connection between calcium and bones?
You have more calcium in your body than any other mineral, and 99% of it is in your 206 bones. Calcium makes your bones strong. If you don't get enough calcium, your bones get fragile and break easily. You may not know you have a problem until you're older, but a lot of the damage--or good--happens when you're a child.
Bone growth often happens in intense, short spurts over just a few days--and probably mostly at night when kids are sleeping. Most calcium is added to your bones by the age of 17. Adults start to lose calcium, especially by late middle age. So the window of opportunity to build strong bones is when you're young.
It's like a bank account to which you can only make permanent deposits in your youth. You want to deposit as much as you can for later. As an adult, the trick is to keep eating calcium-rich foods so that you withdraw as little from your bones as possible.
But most kids aren't saving up at all. In the critical bone-building years starting at age 9 calcium needs double, and only a fraction of kids get enough. That means a lot of broken bones and osteoporosis may be in the future for a whole generation. Osteoporosis is a weakening of the bones that can cause fractures and a hunched-over posture as the bones in the neck and upper back fail to support our heavy heads.
My kids are so busy. They're gone all day and often eat dinner out. How can I make sure they get enough calcium?
Get them to take 10 minutes in the morning to drink a glass of calcium-fortified orange juice and eat a bowl of calcium-fortified cereal with milk (or soy milk enriched with calcium). Add a multivitamin for the vitamin D they also need (plus more calcium). That's about 3 out of the 4 servings they need each day.
Keep low-fat chocolate milk in the fridge. Most kids love it. If they drink that (or have a yogurt or cheese and crackers) in the evening, they're set.
Why do we lose calcium from our bones?
Your body needs calcium to keep your nerves and muscle working, your blood clotting and even for your heart to keep beating regularly. These functions can't wait, so your body takes all the calcium it needs from your bones in a process called remodeling. If you don't constantly replace that calcium, you remodel your skeleton with weaker, more fragile bones. So it's vital that adults preserve their bone strength by eating the right foods.
We tend to think of osteoporosis (weakened bones) as a problem of older women, but men can have it, too. One-fourth of men over age 40 will have an osteoporosis-related fracture at some point. These fractures, especially broken hips, can lead to the end of independent living for many elders.
How much calcium do I need?
It depends on your age. One serving is 300 mg.
1-3 years: 500 mg (almost 2 servings)
4-8 years: 800 mg (almost 3 servings)
9-18 years: 1300 mg (over 4 servings)
19-50 years: 1000 mg (over 3 servings)
51+ years: 1200 mg (4 servings)
What foods have the most calcium?
Each of the Total breakfast cereals has 100% of the adult daily requirement of calcium per serving. The foods below provide about one of the servings of calcium per day that you need:
- 1 cup orange juice fortified with calcium
- 1 cup milk
- 1 cup soy milk fortified with calcium
- 1 cup yogurt
- 1/2 cup part skim ricotta cheese
- 3/4 cup tofu fortified with calcium
- 2 oz. cheese
- 1 medium latte
- 1 large slice cheese pizza
These foods provide about 1/2 serving:
- 1/2 cup pudding made with milk
- 1 cup baked beans
- 1 grilled cheese sandwich
- 1 cup macaroni and cheese
- 1 cup lasagna
- 1 oz. almonds (about 22 nuts)
Soups made with milk, trail mix, waffles and pancakes, other calcium-fortified cereals, spinach, kale and scrambled eggs can also boost your calcium intake.
Choose low-fat or nonfat dairy products to decrease your intake of saturated fat. There's more calcium per serving in low-fat dairy products than in full fat ones.
How much vitamin D do I need each day?
It's hard to say exactly, because your body can make all the vitamin D you need from being in the sun. People rarely developed rickets (severe vitamin D deficiency) until they moved into cities and started working and living indoors in the 1700s. Now we live longer and need to protect our skin from aging and cancer with sunscreen. So our bodies don't make nearly as much vitamin D.
The U.S. recommended daily intake of vitamin D is:
- Birth to age 50: 200 IU
- Age 51 to 69: 400 IU
- 70 and older: 600 IU
But many experts think we need more. Ask you health care provider how much he or she recommends.
What can I do to get more vitamin D?
- Drink more low-fat milk. One cup of milk has about 100 IU of vitamin D. If you aren't crazy about drinking milk, try low-fat chocolate milk. Soups and puddings made with milk provide vitamin D, too.
- Eat more salmon, mackerel, canned tuna or sardines. A 3.5-ounce serving has 200-360 IU of vitamin D.
- Take a multivitamin. Pick a formula that has the right amount of vitamin D for your age and gender.
- Get a little bit of sun. Talk to your provider about your risk for skin cancer. This isn't a good idea for anyone who's at high risk for skin cancer. But for many of us, 5 to 15 minutes of sun on unprotected skin several times a week during spring, summer and fall would allow our bodies to make and store enough vitamin D to last us all winter. Estimate how long it would take you to get sunburned, and spend one fourth of that time in the sun 2 or 3 times a week without sunscreen. That's if you're just exposing your face and hands. The more of your body is exposed, the less time you need in the sun, so if you're in shorts and a sleeveless shirt you can cut the time down to even less. Darker-skinned people need more time than people with lighter skin. Double your time in the sun on cloudy, overcast days.
What if I'm lactose intolerant?
You're far from alone. About 60% of the world's people are lactose intolerant. In fact, scientists are starting to turn the tables. Some of them describe people who can digest lactose (the sugar in milk) as having "lactose persistence." These folks are descendents of dairy farmers in Europe and cattle herders in Africa. They developed gene mutations thousands of years ago that allowed them to digest milk as adults.
If you have gas, bloating or diarrhea when you eat dairy products, you can get the calcium and vitamin D you need from non-dairy fortified foods. See the list of calcium-rich foods above. You could also try eating small quantities of dairy products with meals and you may have fewer symptoms. Yogurt is particularly likely to work for you, and it's very high in calcium. Or try lactose-reduced or lactose-free milk, or lactase drops and tablets.
By the way, lactose intolerance isn't the same as a milk allergy. People with allergies have entirely different symptoms like hives and trouble breathing.
What about calcium supplements?
If you can't get enough calcium in your diet, you may need to take a calcium supplement. They work best if you take them in small doses (no more than 500 mg) several times a day with food.
If you're eating 3 calcium-rich foods a day, you don't need calcium supplements. Studies have not shown any benefit from more calcium than you're already getting.
Doesn't drinking milk stimulate mucus production?
Not unless you're one of the rare people with a true allergy to milk. This myth has been going around since the Middle Ages. For the vast majority of us, drinking milk has no effect on how much mucus we produce. There's no reason to stop drinking milk when you have a cold, or if you have asthma. In fact, young children who consume more foods containing milk fat are less likely to develop asthma.
Is there anything else I can do to keep my bones strong?
You bet. Exercise is great for bones--they get stronger in response to impact and the pull of your muscles. Since exercise helps the specific bones used, do a variety of weight-bearing exercises that get your whole body moving.
You should avoid smoking, alcohol abuse or extreme exercising, which weaken bones. Get treatment if you have an eating disorder, since vomiting or extreme dieting upset the balance of calcium and hormones you need for healthy bones.
Updated on 10/13/09 by J. Johnson (BA English composition, Northwestern University). Published on 11/09/09.
References:
- NEW GUIDELINES DOUBLE THE AMOUNT OF RECOMMENDED VITAMIN D American Academy of Pediatrics (AAP) at http://www.aap.org/pressroom/nce/nce08vitamind.htm
- Milk Matters at http://www.nichd.nih.gov/publications/pubs/upload/strong_bones_lifelong_health_mm1.pdf
- Fall prevention with supplemental and active forms of vitamin D: a meta-analysis of randomised controlled trials H A Bischoff-Ferrari BMJ 2009;339:b3692
- Prevalence and Associations of 25-Hydroxyvitamin D Deficiency in US Children: NHANES 2001-2004 Juhi Kumar PEDIATRICS (doi:10.1542/peds.2009-0051)
- Male Osteoporosis: New Insights in an Understudied Disease Curr Opin Rheumatol. 2008;20(4):423-428.
- The Origins of Lactase Persistence in Europe Yuval Itan PLoS Computational Biology
Learn more about healthy living at Blue Health Connection