Rickets is a disease that happens in young children. It happens in children who do not get enough vitamin D and calcium. It causes larger spaces inside bones, and makes them dry, like sponges. It can make the legs curve toward each other (so the knees touch) or away from each other.
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X-rays and pictures of a child with rickets, showing the leg bones curving inward
Rickets in adults is called osteomalacia.
People need both vitamin D and calcium to make their bones strong.
Vitamin D helps the bones absorb (take up) calcium. Low vitamin D makes it hard to absorb calcium.
The human body makes vitamin D3 in the skin, from cholesterol. Then the liver changes vitamin D3 into calcitriol, which sends calcium from the blood into the bones. The bones need calcium to stay strong. However, the skin will not make vitamin D3 unless enough ultraviolet light shines on it. Sunlight contains ultraviolet light, so getting enough sun is one way of getting enough D3.
Rickets can be prevented if a person gets plenty of calcium and vitamin D.
The best way to do this is to get a lot of sunlight, and eat foods that have a lot of vitamin D and calcium in them. However, people who cannot get enough vitamin D and calcium this way can take supplements (vitamin pills that have calcium and vitamin D in them).
Foods that have a lot of calcium in them include:
- Milk and other dairy products like cheeses
- Some green vegetables, like broccoli, spinach, and kale
- Today, many products are "fortified" with vitamin D: the vitamin was added when the food was made. These foods include some kinds of orange juice, breakfast cereals, breads, and even bottled water. The food's label will say how much calcium it has in it.
Calcium is absorbed best by the bones when it is taken in amounts of 500 – 600 grams or less. Because of this, doctors suggest eating smaller amounts of foods with calcium in them, at different times in the day, instead of all at once.
There are only a few foods that have a lot of vitamin D in them. They include:
- "Fatty fish" that were caught in the wild, like mackerel, salmon, and tuna
- Cooked egg yolk
- Vitamin D is added to some foods, like some kinds of dairy products, cereals, and orange juices
Breast milk may not have enough vitamin D in it to prevent rickets. Babies who are only breastfed, and not fed any other foods, may be given vitamin D drops to make sure they do not get rickets. However, this is not a significant risk if mothers and child have some exposure to sunlight. Children with dark skin are more likely to need additional vitamin D.
These things make a person more likely to get rickets:
- They are between three and 36 months old. Children this age are at the greatest risk for rickets because their bones are growing so quickly, and are supposed to get bigger and stronger during this time
- They were born prematurely (earlier than normal)
- They live in the Northern parts of the world, where there is less sunshine
- They spend too little time outside
- They always wear sunscreen when going out
- Even mild sunscreen decreases the amount of vitamin D the body makes by 95% (by stopping the body from taking in vitamin D from sunlight)
- However, people should still wear sunscreen when they might get sunburned
- They do not eat enough food that has calcium or vitamin D in it, because of lactose intolerance or a strict vegetarian diet
- They cannot make or use vitamin D because of a medical disorder, like coeliac disease, or because they take certain anti-seizure medications
- Cole Jr., Madison B. (2016). "Rickets." World Book Advanced. World Book. Retrieved February 22, 2016.
- "Calcium and Vitamin D: What You Need to Know". National Osteoporosis Foundation. Retrieved March 5, 2016.
- "Rickets." Nutrition and Well-being A-Z. Ed. Delores C.S. James. New York: MacMillan Reference USA, 2004. 2 vols.
- "Rickets: Risk Factors". Mayo Clinic. Mayo Foundation for Education and Research. June 1, 2013. Retrieved March 5, 2016.