Rickets is making a comeback. It's a sign of how our lives are changing — and not for the better. We're seeing this disease, which is caused by a vitamin-D deficiency, in babies and toddlers.
Rickets causes poor bone growth and even deformities. (The name comes from the old English word "wrickken" or twisted.) Vitamin D deficiencies have been reported among school-aged children and adolescents. We're also seeing osteomalacia (weakened bones) in adolescents and adults as a result of vitamin-D deficiency.
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What's Going On?
Vitamin D deficiency is a serious problem. Vitamin D is crucial for bone development. It's also important for other aspects of our health as well: It protects against various cancers and may help prevent diabetes and heart disease.
Vitamin-D deficiency is part of a bigger trend in society that worries me tremendously as a parent and as a pediatrician: The amount of time children spend indoors being sedentary. What does this have to do with vitamin D?
Vitamin D is produced by chemicals in the skin when it is exposed to ultraviolet (UV) light from the sun. That's why vitamin-D deficiency is rarely seen in developing countries where people generally spend a lot of time in the sun.
How Much Is Enough?
It's really hard to say how much sunshine is enough. It depends on your skin color, the latitude where you live, how big you are, and how much skin is exposed.
You don't want to overdo sun exposure. In most cases, a few minutes a few times a week are enough. (Your body stores the vitamin D it makes in those summer days for use in the winter.)
Obviously, you need to be careful with the sun, especially nearer the equator, during peak sunshine hours (between 10 a.m. and 2 p.m.), and particularly with small children as they have years of possible cancer-causing sun exposure ahead of them.
It's still important to use a sunscreen with an SPF 30. This will lessen UV exposure but not screen everything out.
But in countries such as the United States, sun exposure is down for two reasons:
- Concern about skin cancer – We are constantly told that sun exposure can cause skin cancer. So we slather on sunscreen, which blocks the UV light that our bodies need to make vitamin D.
- More time spent indoors – This, I think, is the bigger reason. We are becoming a society that sits inside watching TV, working at our computers, playing video games and surfing the Internet.
Our sedentary lifestyles are having another troubling effect. Currently, a third of U.S. children are either obese or nearly obese. In my inner city pediatric practice, I am seeing a disheartening number of these children — and many of them are also showing signs of vitamin D deficiency.
People with darker skin are at higher risk, because their body naturally blocks some of the UV rays.
Vitamin-D deficiency is also part of some trends in our diets:
- Vitamin D is only available naturally in fatty fish (mackerel, sardines, salmon) and fish oils (such as cod liver oil). Smaller amounts are found in liver and egg yolks. But generally people don't eat a lot of these foods.
- To get enough vitamin D from your diet, you need to eat foods that have vitamin D added to them. These include most commercially prepared milk and dairy products, as well as many cereals. But children, adolescents, and adults who don't eat much dairy or fortified cereal are at risk of becoming vitamin D deficient.
- Vitamin-D deficiency is on the rise is adolescents, many of whom live on junk food and almost entirely indoors.
- Infant formula is fortified with vitamin D, but obviously breast milk is not. Babies who are entirely breastfed are at particular risk of vitamin-D deficiency. So are babies who get some formula and a limited amount of sun.
The American Academy of Pediatrics recommends at least 400 IU daily for infants, children and adolescents. Other important agencies, such as the Institute of Medicine, suggest that children over one year old get 600 IU of vitamin D daily.
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First Things First
So what should parents do? I'd be an irresponsible doctor if my first piece of advice wasn’t GET YOUR KIDS OUTSIDE!
Here are some ideas:
- Let your child burn off some energy by going to the park after school. Sign your child up for a soccer or softball team, or some other outdoor activity.
- Buy some balls for your child to throw or kick around outside — and join in!
- Turn off the TV. If they don't know what to do (this is happening more, as kids rely on videos and less on their own imagination), suggest a scavenger hunt, a game of hide-and-seek or tag, or jump rope.
- Create an obstacle course they have to walk or run through using trash cans, chairs, hula hoops, cardboard boxes.
- Take your children for walks every day. This is a good idea especially for those infants who need some sunshine. It can be a nice way to connect with your children, too — and a way for you to get some exercise! Turn it into a nature hunt by having the kids find the biggest leaf, acorns or other things in season.
- Go fruit-picking. Depending on the season, you can pick berries, apples, peaches — and even pumpkins.
For more ways to get active, check out The President's Council on Physical Fitness and Sports.
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The Need for Supplements
To meet the requirement of 400 I.U. of vitamin D each day, most infants, children and adolescents will need supplements. Here are some guidelines:
- Breastfed babies, or babies who get less than 32 ounces of vitamin D-fortified formula each day, need 400 I.U. of vitamin D daily. Talk to your doctor about which supplement you should use.
- Children and adolescents who aren't drinking 32 ounces of vitamin-D fortified milk or eating other dairy and fortified foods, need a multivitamin with 400 I.U. each day. Children ages 2 and above definitely should drink low-fat milk. Some specialists recommend low-fat milk for 1- to 2- year-olds who are overweight. If you have any questions, ask your doctor.
The return of rickets is sending us an important message that all of us who are responsible for children, especially parents, need to hear. More and more children are not living healthy lives. Vitamin-D deficiency is just one consequence of this; there are many, many more. Get your kids to eat well, move more, shut off the computer and TV, and get outside. Their bones and their lives may depend on it.
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Claire McCarthy, M.D. is an assistant professor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, and medical director of the Martha Eliot Health Center, a neighborhood health service of Children's Hospital. She is a senior medical editor for Harvard Health Publications.